{"id":3742,"date":"2026-05-11T15:29:29","date_gmt":"2026-05-11T08:29:29","guid":{"rendered":"https:\/\/vs.mahidol.ac.th\/mozwe\/?p=3742"},"modified":"2026-05-19T15:20:29","modified_gmt":"2026-05-19T08:20:29","slug":"simpsons-paradox-felv","status":"publish","type":"post","link":"https:\/\/vs.mahidol.ac.th\/mozwe\/en\/simpsons-paradox-felv\/","title":{"rendered":"Simpson\u2019s Paradox: How Latent variables alter conclusions in case of Feline Leukemia virus (FeLV)"},"content":{"rendered":"<style>.wp-block-kadence-advancedheading.kt-adv-heading3742_b60ac2-de, .wp-block-kadence-advancedheading.kt-adv-heading3742_b60ac2-de[data-kb-block=\"kb-adv-heading3742_b60ac2-de\"]{font-style:normal;}.wp-block-kadence-advancedheading.kt-adv-heading3742_b60ac2-de mark.kt-highlight, .wp-block-kadence-advancedheading.kt-adv-heading3742_b60ac2-de[data-kb-block=\"kb-adv-heading3742_b60ac2-de\"] mark.kt-highlight{font-style:normal;color:#f76a0c;-webkit-box-decoration-break:clone;box-decoration-break:clone;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.wp-block-kadence-advancedheading.kt-adv-heading3742_b60ac2-de img.kb-inline-image, .wp-block-kadence-advancedheading.kt-adv-heading3742_b60ac2-de[data-kb-block=\"kb-adv-heading3742_b60ac2-de\"] img.kb-inline-image{width:150px;vertical-align:baseline;}<\/style>\n<h2 class=\"kt-adv-heading3742_b60ac2-de wp-block-kadence-advancedheading\" data-kb-block=\"kb-adv-heading3742_b60ac2-de\"><br><strong>The classic example of a Simpson\u2019s<\/strong> <strong>paradox<\/strong><\/h2>\n\n\n<style>.wp-block-kadence-advancedheading.kt-adv-heading3742_e7209d-81, .wp-block-kadence-advancedheading.kt-adv-heading3742_e7209d-81[data-kb-block=\"kb-adv-heading3742_e7209d-81\"]{font-style:normal;}.wp-block-kadence-advancedheading.kt-adv-heading3742_e7209d-81 mark.kt-highlight, .wp-block-kadence-advancedheading.kt-adv-heading3742_e7209d-81[data-kb-block=\"kb-adv-heading3742_e7209d-81\"] mark.kt-highlight{font-style:normal;color:#f76a0c;-webkit-box-decoration-break:clone;box-decoration-break:clone;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.wp-block-kadence-advancedheading.kt-adv-heading3742_e7209d-81 img.kb-inline-image, .wp-block-kadence-advancedheading.kt-adv-heading3742_e7209d-81[data-kb-block=\"kb-adv-heading3742_e7209d-81\"] img.kb-inline-image{width:150px;vertical-align:baseline;}<\/style>\n<p class=\"kt-adv-heading3742_e7209d-81 wp-block-kadence-advancedheading\" data-kb-block=\"kb-adv-heading3742_e7209d-81\">When analyzing data, we sometimes get unusual results that contradict previous research.&nbsp;<\/p>\n\n\n<style>.wp-block-kadence-advancedheading.kt-adv-heading3742_2abcb9-bd, .wp-block-kadence-advancedheading.kt-adv-heading3742_2abcb9-bd[data-kb-block=\"kb-adv-heading3742_2abcb9-bd\"]{font-style:normal;}.wp-block-kadence-advancedheading.kt-adv-heading3742_2abcb9-bd mark.kt-highlight, .wp-block-kadence-advancedheading.kt-adv-heading3742_2abcb9-bd[data-kb-block=\"kb-adv-heading3742_2abcb9-bd\"] mark.kt-highlight{font-style:normal;color:#f76a0c;-webkit-box-decoration-break:clone;box-decoration-break:clone;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.wp-block-kadence-advancedheading.kt-adv-heading3742_2abcb9-bd img.kb-inline-image, .wp-block-kadence-advancedheading.kt-adv-heading3742_2abcb9-bd[data-kb-block=\"kb-adv-heading3742_2abcb9-bd\"] img.kb-inline-image{width:150px;vertical-align:baseline;}<\/style>\n<p class=\"kt-adv-heading3742_2abcb9-bd wp-block-kadence-advancedheading\" data-kb-block=\"kb-adv-heading3742_2abcb9-bd\">In 1996, researchers presented an interesting result from a twenty-year follow-up of the Whickham Survey. A part of the study, which included 1,314 women, showed that <strong>smokers in this study appeared to live longer (76% 443\/582) than women who had never smoked (69% 502\/732)<\/strong>. This finding seems to go against scientific evidence about the harms of smoking. (Table 1)<\/p>\n\n\n<style>.kb-row-layout-id3742_f4597f-08 > .kt-row-column-wrap{align-content:start;}:where(.kb-row-layout-id3742_f4597f-08 > .kt-row-column-wrap) > .wp-block-kadence-column{justify-content:start;}.kb-row-layout-id3742_f4597f-08 > .kt-row-column-wrap{column-gap:var(--global-kb-gap-md, 2rem);row-gap:var(--global-kb-gap-md, 2rem);padding-top:var(--global-kb-spacing-sm, 1.5rem);padding-bottom:var(--global-kb-spacing-sm, 1.5rem);grid-template-columns:minmax(0, 1fr);}.kb-row-layout-id3742_f4597f-08 > .kt-row-layout-overlay{opacity:0.30;}@media all and (max-width: 1024px){.kb-row-layout-id3742_f4597f-08 > .kt-row-column-wrap{grid-template-columns:minmax(0, 1fr);}}@media all and (max-width: 767px){.kb-row-layout-id3742_f4597f-08 > .kt-row-column-wrap{grid-template-columns:minmax(0, 1fr);}}<\/style><div class=\"kb-row-layout-wrap kb-row-layout-id3742_f4597f-08 alignnone wp-block-kadence-rowlayout\"><div class=\"kt-row-column-wrap kt-has-1-columns kt-row-layout-equal kt-tab-layout-inherit kt-mobile-layout-row kt-row-valign-top\">\n<style>.kadence-column3742_e3502e-cc > .kt-inside-inner-col,.kadence-column3742_e3502e-cc > .kt-inside-inner-col:before{border-top-left-radius:0px;border-top-right-radius:0px;border-bottom-right-radius:0px;border-bottom-left-radius:0px;}.kadence-column3742_e3502e-cc > .kt-inside-inner-col{column-gap:var(--global-kb-gap-sm, 1rem);}.kadence-column3742_e3502e-cc > .kt-inside-inner-col{flex-direction:column;}.kadence-column3742_e3502e-cc > .kt-inside-inner-col > .aligncenter{width:100%;}.kadence-column3742_e3502e-cc > .kt-inside-inner-col:before{opacity:0.3;}.kadence-column3742_e3502e-cc{position:relative;}@media all and (max-width: 1024px){.kadence-column3742_e3502e-cc > .kt-inside-inner-col{flex-direction:column;justify-content:center;}}@media all and (max-width: 767px){.kadence-column3742_e3502e-cc > .kt-inside-inner-col{flex-direction:column;justify-content:center;}}<\/style>\n<div class=\"wp-block-kadence-column kadence-column3742_e3502e-cc\"><div class=\"kt-inside-inner-col\"><style>.kb-gallery-id-3742_cb300c-29 .kadence-blocks-gallery-item .kb-gal-image-radius, .kb-gallery-id-3742_cb300c-29 .kb-slide-item .kb-gal-image-radius img{border-radius:0px 0px 0px 0px;;}.kb-gallery-caption-style-bottom.kb-gallery-id-3742_cb300c-29 .kadence-blocks-gallery-item .kadence-blocks-gallery-item-inner .kadence-blocks-gallery-item__caption, .kb-gallery-caption-style-bottom-hover.kb-gallery-id-3742_cb300c-29 .kadence-blocks-gallery-item .kadence-blocks-gallery-item-inner .kadence-blocks-gallery-item__caption{background:linear-gradient(0deg, rgba(0, 0, 0, 0.8) 0, rgba(0, 0, 0, 0) 100%);}.kb-gallery-wrap-id-3742_cb300c-29.wp-block-kadence-advancedgallery{overflow:visible;}.kb-gallery-wrap-id-3742_cb300c-29.wp-block-kadence-advancedgallery .kt-blocks-carousel{overflow:visible;}<\/style><div class=\"kb-gallery-wrap-id-3742_cb300c-29 alignnone wp-block-kadence-advancedgallery\"><div class=\"kb-gallery-ul kb-gallery-non-static kb-gallery-type-slider kb-gallery-id-3742_cb300c-29 kb-gallery-caption-style-bottom-hover kb-gallery-filter-none kb-gallery-magnific-init\" data-image-filter=\"none\" data-lightbox-caption=\"true\"><div class=\"kt-blocks-carousel splide kt-carousel-container-dotstyle-dark kt-carousel-arrowstyle-none kt-carousel-dotstyle-dark kb-slider-group-arrow kb-slider-arrow-position-center\" data-slider-anim-speed=\"400\" data-slider-scroll=\"1\" data-slider-arrows=\"false\" data-slider-fade=\"true\" data-slider-dots=\"true\" data-slider-type=\"slider\" data-slider-hover-pause=\"false\" data-slider-auto=\"\" data-slider-speed=\"7000\" data-show-pause-button=\"false\"><div class=\"splide__track\"><ul class=\"kt-blocks-carousel-init kb-blocks-slider splide__list\"><li class=\"kb-slide-item kb-gallery-slide-item splide__slide\"><div class=\"kadence-blocks-gallery-item\"><div class=\"kadence-blocks-gallery-item-inner\"><figure class=\"kb-gallery-figure kb-gallery-item-has-link kadence-blocks-gallery-item-has-caption\"><a href=\"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-content\/uploads\/2026\/05\/SimpsonParadox-1.png\" data-description=\"Table 1. Relationship Between Smoking Habits and 20-Year Survival in 1,314 Women\" class=\"kb-gallery-item-link\"   role=\"button\" aria-haspopup=\"dialog\"><div class=\"kb-gal-image-radius\"><div class=\"kb-gallery-image-contain kadence-blocks-gallery-intrinsic kb-gallery-image-ratio-land21 kb-has-image-ratio-land21\" ><img loading=\"lazy\" decoding=\"async\" src=\"data:image\/svg+xml,%3Csvg%20xmlns='http:\/\/www.w3.org\/2000\/svg'%20viewBox='0%200%201000%20667'%3E%3C\/svg%3E\"  data-splide-lazy=\"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-content\/uploads\/2026\/05\/SimpsonParadox-1.png\" width=\"1200\" height=\"600\" alt=\"\" data-full-image=\"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-content\/uploads\/2026\/05\/SimpsonParadox-1.png\" data-light-image=\"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-content\/uploads\/2026\/05\/SimpsonParadox-1.png\" data-id=\"3744\" class=\"wp-image-3744 skip-lazy\"\/><\/div><div class=\"kadence-blocks-gallery-item__caption\"><strong>Table 1. Relationship Between Smoking Habits and 20-Year Survival in 1,314 Women<\/strong><\/div><\/div><\/a><\/figure><\/div><\/div><\/li><\/ul><\/div><\/div><\/div><\/div>\n\n<style>.wp-block-kadence-advancedheading.kt-adv-heading3742_743f50-ee, .wp-block-kadence-advancedheading.kt-adv-heading3742_743f50-ee[data-kb-block=\"kb-adv-heading3742_743f50-ee\"]{text-align:center;font-size:var(--global-kb-font-size-sm, 0.9rem);font-style:normal;}.wp-block-kadence-advancedheading.kt-adv-heading3742_743f50-ee mark.kt-highlight, .wp-block-kadence-advancedheading.kt-adv-heading3742_743f50-ee[data-kb-block=\"kb-adv-heading3742_743f50-ee\"] mark.kt-highlight{font-style:normal;color:#f76a0c;-webkit-box-decoration-break:clone;box-decoration-break:clone;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.wp-block-kadence-advancedheading.kt-adv-heading3742_743f50-ee img.kb-inline-image, .wp-block-kadence-advancedheading.kt-adv-heading3742_743f50-ee[data-kb-block=\"kb-adv-heading3742_743f50-ee\"] img.kb-inline-image{width:150px;vertical-align:baseline;}<\/style>\n<p class=\"kt-adv-heading3742_743f50-ee wp-block-kadence-advancedheading\" data-kb-block=\"kb-adv-heading3742_743f50-ee\"><strong>Table 1. Relationship Between Smoking Habits and 20-Year Survival in 1,314 Women<\/strong><br><strong><em>[Adapted from <\/em><\/strong><em>Appleton, D. R., French, J. M., &amp; Vanderpump, M. P. J. (1996). Ignoring a covariate: An example of Simpson&#8217;s paradox. The American Statistician, 50(4), 340-341. <\/em><a href=\"https:\/\/doi.org\/10.1080\/00031305.1996.10473563\"><em>https:\/\/doi.org\/10.1080\/00031305.1996.10473563<\/em><\/a><em> <\/em><strong><em>]<\/em><\/strong><\/p>\n<\/div><\/div>\n\n<\/div><\/div>\n\n<style>.wp-block-kadence-advancedheading.kt-adv-heading3742_ef7d9a-6f, .wp-block-kadence-advancedheading.kt-adv-heading3742_ef7d9a-6f[data-kb-block=\"kb-adv-heading3742_ef7d9a-6f\"]{font-style:normal;}.wp-block-kadence-advancedheading.kt-adv-heading3742_ef7d9a-6f mark.kt-highlight, .wp-block-kadence-advancedheading.kt-adv-heading3742_ef7d9a-6f[data-kb-block=\"kb-adv-heading3742_ef7d9a-6f\"] mark.kt-highlight{font-style:normal;color:#f76a0c;-webkit-box-decoration-break:clone;box-decoration-break:clone;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.wp-block-kadence-advancedheading.kt-adv-heading3742_ef7d9a-6f img.kb-inline-image, .wp-block-kadence-advancedheading.kt-adv-heading3742_ef7d9a-6f[data-kb-block=\"kb-adv-heading3742_ef7d9a-6f\"] img.kb-inline-image{width:150px;vertical-align:baseline;}<\/style>\n<p class=\"kt-adv-heading3742_ef7d9a-6f wp-block-kadence-advancedheading\" data-kb-block=\"kb-adv-heading3742_ef7d9a-6f\">But when looking into the data separated by age, the group of smokers in almost all age groups had a higher mortality rate than the non-smoker group. (Table 2)<\/p>\n\n\n<style>.kb-row-layout-id3742_840a52-61 > .kt-row-column-wrap{align-content:start;}:where(.kb-row-layout-id3742_840a52-61 > .kt-row-column-wrap) > .wp-block-kadence-column{justify-content:start;}.kb-row-layout-id3742_840a52-61 > .kt-row-column-wrap{column-gap:var(--global-kb-gap-md, 2rem);row-gap:var(--global-kb-gap-md, 2rem);padding-top:var(--global-kb-spacing-sm, 1.5rem);padding-bottom:var(--global-kb-spacing-sm, 1.5rem);grid-template-columns:minmax(0, 1fr);}.kb-row-layout-id3742_840a52-61 > .kt-row-layout-overlay{opacity:0.30;}@media all and (max-width: 1024px){.kb-row-layout-id3742_840a52-61 > .kt-row-column-wrap{grid-template-columns:minmax(0, 1fr);}}@media all and (max-width: 767px){.kb-row-layout-id3742_840a52-61 > .kt-row-column-wrap{grid-template-columns:minmax(0, 1fr);}}<\/style><div class=\"kb-row-layout-wrap kb-row-layout-id3742_840a52-61 alignnone wp-block-kadence-rowlayout\"><div class=\"kt-row-column-wrap kt-has-1-columns kt-row-layout-equal kt-tab-layout-inherit kt-mobile-layout-row kt-row-valign-top\">\n<style>.kadence-column3742_3f257b-d0 > .kt-inside-inner-col,.kadence-column3742_3f257b-d0 > .kt-inside-inner-col:before{border-top-left-radius:0px;border-top-right-radius:0px;border-bottom-right-radius:0px;border-bottom-left-radius:0px;}.kadence-column3742_3f257b-d0 > .kt-inside-inner-col{column-gap:var(--global-kb-gap-sm, 1rem);}.kadence-column3742_3f257b-d0 > .kt-inside-inner-col{flex-direction:column;}.kadence-column3742_3f257b-d0 > .kt-inside-inner-col > .aligncenter{width:100%;}.kadence-column3742_3f257b-d0 > .kt-inside-inner-col:before{opacity:0.3;}.kadence-column3742_3f257b-d0{position:relative;}@media all and (max-width: 1024px){.kadence-column3742_3f257b-d0 > .kt-inside-inner-col{flex-direction:column;justify-content:center;}}@media all and (max-width: 767px){.kadence-column3742_3f257b-d0 > .kt-inside-inner-col{flex-direction:column;justify-content:center;}}<\/style>\n<div class=\"wp-block-kadence-column kadence-column3742_3f257b-d0\"><div class=\"kt-inside-inner-col\"><style>.kb-gallery-id-3742_4ca54f-b8 .kadence-blocks-gallery-item .kb-gal-image-radius, .kb-gallery-id-3742_4ca54f-b8 .kb-slide-item .kb-gal-image-radius img{border-radius:0px 0px 0px 0px;;}.kb-gallery-caption-style-bottom.kb-gallery-id-3742_4ca54f-b8 .kadence-blocks-gallery-item .kadence-blocks-gallery-item-inner .kadence-blocks-gallery-item__caption, .kb-gallery-caption-style-bottom-hover.kb-gallery-id-3742_4ca54f-b8 .kadence-blocks-gallery-item .kadence-blocks-gallery-item-inner .kadence-blocks-gallery-item__caption{background:linear-gradient(0deg, rgba(0, 0, 0, 0.8) 0, rgba(0, 0, 0, 0) 100%);}.kb-gallery-wrap-id-3742_4ca54f-b8.wp-block-kadence-advancedgallery{overflow:visible;}.kb-gallery-wrap-id-3742_4ca54f-b8.wp-block-kadence-advancedgallery .kt-blocks-carousel{overflow:visible;}<\/style><div class=\"kb-gallery-wrap-id-3742_4ca54f-b8 alignnone wp-block-kadence-advancedgallery\"><div class=\"kb-gallery-ul kb-gallery-non-static kb-gallery-type-slider kb-gallery-id-3742_4ca54f-b8 kb-gallery-caption-style-bottom-hover kb-gallery-filter-none kb-gallery-magnific-init\" data-image-filter=\"none\" data-lightbox-caption=\"true\"><div class=\"kt-blocks-carousel splide kt-carousel-container-dotstyle-dark kt-carousel-arrowstyle-none kt-carousel-dotstyle-dark kb-slider-group-arrow kb-slider-arrow-position-center\" data-slider-anim-speed=\"400\" data-slider-scroll=\"1\" data-slider-arrows=\"false\" data-slider-fade=\"true\" data-slider-dots=\"true\" data-slider-type=\"slider\" data-slider-hover-pause=\"false\" data-slider-auto=\"\" data-slider-speed=\"7000\" data-show-pause-button=\"false\"><div class=\"splide__track\"><ul class=\"kt-blocks-carousel-init kb-blocks-slider splide__list\"><li class=\"kb-slide-item kb-gallery-slide-item splide__slide\"><div class=\"kadence-blocks-gallery-item\"><div class=\"kadence-blocks-gallery-item-inner\"><figure class=\"kb-gallery-figure kb-gallery-item-has-link\"><a href=\"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-content\/uploads\/2026\/05\/SimpsonParadox-2-1.png\" class=\"kb-gallery-item-link\"   role=\"button\" aria-haspopup=\"dialog\"><div class=\"kb-gal-image-radius\"><div class=\"kb-gallery-image-contain kadence-blocks-gallery-intrinsic kb-gallery-image-ratio-inherit kb-has-image-ratio-inherit\" ><img loading=\"lazy\" decoding=\"async\" src=\"data:image\/svg+xml,%3Csvg%20xmlns='http:\/\/www.w3.org\/2000\/svg'%20viewBox='0%200%201000%20667'%3E%3C\/svg%3E\"  data-splide-lazy=\"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-content\/uploads\/2026\/05\/SimpsonParadox-2-1.png\" width=\"1200\" height=\"600\" alt=\"\" data-full-image=\"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-content\/uploads\/2026\/05\/SimpsonParadox-2-1.png\" data-light-image=\"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-content\/uploads\/2026\/05\/SimpsonParadox-2-1.png\" data-id=\"3751\" class=\"wp-image-3751 skip-lazy\"\/><\/div><\/div><\/a><\/figure><\/div><\/div><\/li><\/ul><\/div><\/div><\/div><\/div>\n\n<style>.wp-block-kadence-advancedheading.kt-adv-heading3742_3e72a7-91, .wp-block-kadence-advancedheading.kt-adv-heading3742_3e72a7-91[data-kb-block=\"kb-adv-heading3742_3e72a7-91\"]{text-align:center;font-size:var(--global-kb-font-size-sm, 0.9rem);font-style:normal;}.wp-block-kadence-advancedheading.kt-adv-heading3742_3e72a7-91 mark.kt-highlight, .wp-block-kadence-advancedheading.kt-adv-heading3742_3e72a7-91[data-kb-block=\"kb-adv-heading3742_3e72a7-91\"] mark.kt-highlight{font-style:normal;color:#f76a0c;-webkit-box-decoration-break:clone;box-decoration-break:clone;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.wp-block-kadence-advancedheading.kt-adv-heading3742_3e72a7-91 img.kb-inline-image, .wp-block-kadence-advancedheading.kt-adv-heading3742_3e72a7-91[data-kb-block=\"kb-adv-heading3742_3e72a7-91\"] img.kb-inline-image{width:150px;vertical-align:baseline;}<\/style>\n<p class=\"kt-adv-heading3742_3e72a7-91 wp-block-kadence-advancedheading\" data-kb-block=\"kb-adv-heading3742_3e72a7-91\"><strong>Table 2 Number of Women smokers and Non-smokers in different age groups, showing their 20-year survival status.<\/strong><br><strong><em>[Adapted from <\/em><\/strong><em>Appleton, D. R., French, J. M., &amp; Vanderpump, M. P. J. (1996). Ignoring a covariate: An example of Simpson&#8217;s paradox. The American Statistician, 50(4), 340-341. <\/em><a href=\"https:\/\/doi.org\/10.1080\/00031305.1996.10473563\"><em>https:\/\/doi.org\/10.1080\/00031305.1996.10473563<\/em><\/a><em>\u00a0<\/em><strong><em>]<\/em><\/strong><\/p>\n<\/div><\/div>\n\n<\/div><\/div>\n\n<style>.kb-row-layout-id3742_f5d06a-48 > .kt-row-column-wrap{align-content:start;}:where(.kb-row-layout-id3742_f5d06a-48 > .kt-row-column-wrap) > .wp-block-kadence-column{justify-content:start;}.kb-row-layout-id3742_f5d06a-48 > .kt-row-column-wrap{column-gap:var(--global-kb-gap-md, 2rem);row-gap:var(--global-kb-gap-md, 2rem);padding-top:var(--global-kb-spacing-sm, 1.5rem);padding-bottom:var(--global-kb-spacing-sm, 1.5rem);grid-template-columns:minmax(0, 1fr);}.kb-row-layout-id3742_f5d06a-48 > .kt-row-layout-overlay{opacity:0.30;}@media all and (max-width: 1024px){.kb-row-layout-id3742_f5d06a-48 > .kt-row-column-wrap{grid-template-columns:minmax(0, 1fr);}}@media all and (max-width: 767px){.kb-row-layout-id3742_f5d06a-48 > .kt-row-column-wrap{grid-template-columns:minmax(0, 1fr);}}<\/style><div class=\"kb-row-layout-wrap kb-row-layout-id3742_f5d06a-48 alignnone wp-block-kadence-rowlayout\"><div class=\"kt-row-column-wrap kt-has-1-columns kt-row-layout-equal kt-tab-layout-inherit kt-mobile-layout-row kt-row-valign-top\">\n<style>.kadence-column3742_91f12d-69 > .kt-inside-inner-col,.kadence-column3742_91f12d-69 > .kt-inside-inner-col:before{border-top-left-radius:0px;border-top-right-radius:0px;border-bottom-right-radius:0px;border-bottom-left-radius:0px;}.kadence-column3742_91f12d-69 > .kt-inside-inner-col{column-gap:var(--global-kb-gap-sm, 1rem);}.kadence-column3742_91f12d-69 > .kt-inside-inner-col{flex-direction:column;}.kadence-column3742_91f12d-69 > .kt-inside-inner-col > .aligncenter{width:100%;}.kadence-column3742_91f12d-69 > .kt-inside-inner-col:before{opacity:0.3;}.kadence-column3742_91f12d-69{position:relative;}@media all and (max-width: 1024px){.kadence-column3742_91f12d-69 > .kt-inside-inner-col{flex-direction:column;justify-content:center;}}@media all and (max-width: 767px){.kadence-column3742_91f12d-69 > .kt-inside-inner-col{flex-direction:column;justify-content:center;}}<\/style>\n<div class=\"wp-block-kadence-column kadence-column3742_91f12d-69\"><div class=\"kt-inside-inner-col\"><style>.wp-block-kadence-advancedheading.kt-adv-heading3742_98f320-ef, .wp-block-kadence-advancedheading.kt-adv-heading3742_98f320-ef[data-kb-block=\"kb-adv-heading3742_98f320-ef\"]{font-style:normal;}.wp-block-kadence-advancedheading.kt-adv-heading3742_98f320-ef mark.kt-highlight, .wp-block-kadence-advancedheading.kt-adv-heading3742_98f320-ef[data-kb-block=\"kb-adv-heading3742_98f320-ef\"] mark.kt-highlight{font-style:normal;color:#f76a0c;-webkit-box-decoration-break:clone;box-decoration-break:clone;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.wp-block-kadence-advancedheading.kt-adv-heading3742_98f320-ef img.kb-inline-image, .wp-block-kadence-advancedheading.kt-adv-heading3742_98f320-ef[data-kb-block=\"kb-adv-heading3742_98f320-ef\"] img.kb-inline-image{width:150px;vertical-align:baseline;}<\/style>\n<p class=\"kt-adv-heading3742_98f320-ef wp-block-kadence-advancedheading\" data-kb-block=\"kb-adv-heading3742_98f320-ef\">The findings of this study are controversial and have differed across various studies. Therefore, the conclusions drawn must be considered carefully. Sometimes, statistical errors can arise when comparing the averages or correlations within each group to those of the combined data, leading to trends that may conflict. This conflicting result is known as Simpson\u2019s Paradox, where group-level trends can differ from the overall trend.<\/p>\n<\/div><\/div>\n\n<\/div><\/div>\n\n<style>.wp-block-kadence-spacer.kt-block-spacer-3742_115b1b-01 .kt-block-spacer{height:60px;}.wp-block-kadence-spacer.kt-block-spacer-3742_115b1b-01 .kt-divider{border-top-width:1px;height:1px;border-top-color:#eee;width:80%;border-top-style:solid;}<\/style>\n<div class=\"wp-block-kadence-spacer aligncenter kt-block-spacer-3742_115b1b-01\"><div class=\"kt-block-spacer kt-block-spacer-halign-center\"><hr class=\"kt-divider\"\/><\/div><\/div>\n\n\n<style>.wp-block-kadence-advancedheading.kt-adv-heading3742_969deb-07, .wp-block-kadence-advancedheading.kt-adv-heading3742_969deb-07[data-kb-block=\"kb-adv-heading3742_969deb-07\"]{font-style:normal;}.wp-block-kadence-advancedheading.kt-adv-heading3742_969deb-07 mark.kt-highlight, .wp-block-kadence-advancedheading.kt-adv-heading3742_969deb-07[data-kb-block=\"kb-adv-heading3742_969deb-07\"] mark.kt-highlight{font-style:normal;color:#f76a0c;-webkit-box-decoration-break:clone;box-decoration-break:clone;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.wp-block-kadence-advancedheading.kt-adv-heading3742_969deb-07 img.kb-inline-image, .wp-block-kadence-advancedheading.kt-adv-heading3742_969deb-07[data-kb-block=\"kb-adv-heading3742_969deb-07\"] img.kb-inline-image{width:150px;vertical-align:baseline;}<\/style>\n<h2 class=\"kt-adv-heading3742_969deb-07 wp-block-kadence-advancedheading\" data-kb-block=\"kb-adv-heading3742_969deb-07\"><strong>What is Simpson\u2019s Paradox?<\/strong><\/h2>\n\n\n\n<figure class=\"wp-block-pullquote has-text-align-center has-bg-2-background-color has-background\" style=\"border-top-left-radius:0px;border-top-right-radius:0px;border-bottom-left-radius:0px;border-bottom-right-radius:0px;font-size:10px\"><blockquote><p><strong>Simpson\u2019s Paradox<\/strong> is a statistical phenomenon where an association between two variables in a population emerges, disappears or reverses when the population is divided into subpopulations. For instance, two variables may be positively associated in a population, but be independent or even negatively associated in all subpopulations. Cases exhibiting the paradox are unproblematic from the perspective of mathematics and probability theory, but nevertheless strike many people as surprising. Additionally, the paradox has implications for a range of areas that rely on probabilities, including decision theory, causal inference, and evolutionary biology. Finally, there are many instances of the paradox, including in epidemiology and in studies of discrimination, where understanding the paradox is essential for drawing the correct conclusions from the data.<\/p><cite>Simpson\u2019s Paradox (Stanford Encyclopedia of Philosophy)<br><a href=\"https:\/\/plato.stanford.edu\/ENTRIES\/paradox-simpson\/\"> https:\/\/plato.stanford.edu\/ENTRIES\/paradox-simpson\/<\/a><\/cite><\/blockquote><\/figure>\n\n\n<style>.wp-block-kadence-advancedheading.kt-adv-heading3742_f0f3df-05, .wp-block-kadence-advancedheading.kt-adv-heading3742_f0f3df-05[data-kb-block=\"kb-adv-heading3742_f0f3df-05\"]{font-style:normal;}.wp-block-kadence-advancedheading.kt-adv-heading3742_f0f3df-05 mark.kt-highlight, .wp-block-kadence-advancedheading.kt-adv-heading3742_f0f3df-05[data-kb-block=\"kb-adv-heading3742_f0f3df-05\"] mark.kt-highlight{font-style:normal;color:#f76a0c;-webkit-box-decoration-break:clone;box-decoration-break:clone;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.wp-block-kadence-advancedheading.kt-adv-heading3742_f0f3df-05 img.kb-inline-image, .wp-block-kadence-advancedheading.kt-adv-heading3742_f0f3df-05[data-kb-block=\"kb-adv-heading3742_f0f3df-05\"] img.kb-inline-image{width:150px;vertical-align:baseline;}<\/style>\n<h2 class=\"kt-adv-heading3742_f0f3df-05 wp-block-kadence-advancedheading\" data-kb-block=\"kb-adv-heading3742_f0f3df-05\"><strong>FeLV case from our database<\/strong><\/h2>\n\n\n<style>.wp-block-kadence-advancedheading.kt-adv-heading3742_3c8af6-30, .wp-block-kadence-advancedheading.kt-adv-heading3742_3c8af6-30[data-kb-block=\"kb-adv-heading3742_3c8af6-30\"]{font-style:normal;}.wp-block-kadence-advancedheading.kt-adv-heading3742_3c8af6-30 mark.kt-highlight, .wp-block-kadence-advancedheading.kt-adv-heading3742_3c8af6-30[data-kb-block=\"kb-adv-heading3742_3c8af6-30\"] mark.kt-highlight{font-style:normal;color:#f76a0c;-webkit-box-decoration-break:clone;box-decoration-break:clone;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.wp-block-kadence-advancedheading.kt-adv-heading3742_3c8af6-30 img.kb-inline-image, .wp-block-kadence-advancedheading.kt-adv-heading3742_3c8af6-30[data-kb-block=\"kb-adv-heading3742_3c8af6-30\"] img.kb-inline-image{width:150px;vertical-align:baseline;}<\/style>\n<p class=\"kt-adv-heading3742_3c8af6-30 wp-block-kadence-advancedheading\" data-kb-block=\"kb-adv-heading3742_3c8af6-30\">Let&#8217;s examine an interesting example in which summarizing the same dataset yields different conclusions. In the case of the feline leukemia virus (FeLV) from the <strong>MoZWE database<\/strong>, classify the data by sex for 932 samples, as shown in the table below.<\/p>\n\n\n<style>.kb-row-layout-id3742_236c20-b3 > .kt-row-column-wrap{align-content:start;}:where(.kb-row-layout-id3742_236c20-b3 > .kt-row-column-wrap) > .wp-block-kadence-column{justify-content:start;}.kb-row-layout-id3742_236c20-b3 > .kt-row-column-wrap{column-gap:var(--global-kb-gap-md, 2rem);row-gap:var(--global-kb-gap-md, 2rem);padding-top:var(--global-kb-spacing-sm, 1.5rem);padding-bottom:var(--global-kb-spacing-sm, 1.5rem);grid-template-columns:minmax(0, 1fr);}.kb-row-layout-id3742_236c20-b3 > .kt-row-layout-overlay{opacity:0.30;}@media all and (max-width: 1024px){.kb-row-layout-id3742_236c20-b3 > .kt-row-column-wrap{grid-template-columns:minmax(0, 1fr);}}@media all and (max-width: 767px){.kb-row-layout-id3742_236c20-b3 > .kt-row-column-wrap{grid-template-columns:minmax(0, 1fr);}}<\/style><div class=\"kb-row-layout-wrap kb-row-layout-id3742_236c20-b3 alignnone wp-block-kadence-rowlayout\"><div class=\"kt-row-column-wrap kt-has-1-columns kt-row-layout-equal kt-tab-layout-inherit kt-mobile-layout-row kt-row-valign-top\">\n<style>.kadence-column3742_393747-dc > .kt-inside-inner-col,.kadence-column3742_393747-dc > .kt-inside-inner-col:before{border-top-left-radius:0px;border-top-right-radius:0px;border-bottom-right-radius:0px;border-bottom-left-radius:0px;}.kadence-column3742_393747-dc > .kt-inside-inner-col{column-gap:var(--global-kb-gap-sm, 1rem);}.kadence-column3742_393747-dc > .kt-inside-inner-col{flex-direction:column;}.kadence-column3742_393747-dc > .kt-inside-inner-col > .aligncenter{width:100%;}.kadence-column3742_393747-dc > .kt-inside-inner-col:before{opacity:0.3;}.kadence-column3742_393747-dc{position:relative;}@media all and (max-width: 1024px){.kadence-column3742_393747-dc > .kt-inside-inner-col{flex-direction:column;justify-content:center;}}@media all and (max-width: 767px){.kadence-column3742_393747-dc > .kt-inside-inner-col{flex-direction:column;justify-content:center;}}<\/style>\n<div class=\"wp-block-kadence-column kadence-column3742_393747-dc\"><div class=\"kt-inside-inner-col\"><style>.kb-gallery-id-3742_fb7443-d4 .kadence-blocks-gallery-item .kb-gal-image-radius, .kb-gallery-id-3742_fb7443-d4 .kb-slide-item .kb-gal-image-radius img{border-radius:0px 0px 0px 0px;;}.kb-gallery-caption-style-bottom.kb-gallery-id-3742_fb7443-d4 .kadence-blocks-gallery-item .kadence-blocks-gallery-item-inner .kadence-blocks-gallery-item__caption, .kb-gallery-caption-style-bottom-hover.kb-gallery-id-3742_fb7443-d4 .kadence-blocks-gallery-item .kadence-blocks-gallery-item-inner .kadence-blocks-gallery-item__caption{background:linear-gradient(0deg, rgba(0, 0, 0, 0.8) 0, rgba(0, 0, 0, 0) 100%);}.kb-gallery-wrap-id-3742_fb7443-d4.wp-block-kadence-advancedgallery{overflow:visible;}.kb-gallery-wrap-id-3742_fb7443-d4.wp-block-kadence-advancedgallery .kt-blocks-carousel{overflow:visible;}<\/style><div class=\"kb-gallery-wrap-id-3742_fb7443-d4 alignnone wp-block-kadence-advancedgallery\"><div class=\"kb-gallery-ul kb-gallery-non-static kb-gallery-type-slider kb-gallery-id-3742_fb7443-d4 kb-gallery-caption-style-bottom-hover kb-gallery-filter-none kb-gallery-magnific-init\" data-image-filter=\"none\" data-lightbox-caption=\"true\"><div class=\"kt-blocks-carousel splide kt-carousel-container-dotstyle-dark kt-carousel-arrowstyle-none kt-carousel-dotstyle-dark kb-slider-group-arrow kb-slider-arrow-position-center\" data-slider-anim-speed=\"400\" data-slider-scroll=\"1\" data-slider-arrows=\"false\" data-slider-fade=\"true\" data-slider-dots=\"true\" data-slider-type=\"slider\" data-slider-hover-pause=\"false\" data-slider-auto=\"\" data-slider-speed=\"7000\" data-show-pause-button=\"false\"><div class=\"splide__track\"><ul class=\"kt-blocks-carousel-init kb-blocks-slider splide__list\"><li class=\"kb-slide-item kb-gallery-slide-item splide__slide\"><div class=\"kadence-blocks-gallery-item\"><div class=\"kadence-blocks-gallery-item-inner\"><figure class=\"kb-gallery-figure kb-gallery-item-has-link kadence-blocks-gallery-item-has-caption\"><a href=\"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-content\/uploads\/2026\/05\/SimpsonParadox-3-1.png\" data-description=\"Table 3. Sample with positive result in feline leukemia virus classified by sex with 932 animal samples\" class=\"kb-gallery-item-link\"   role=\"button\" aria-haspopup=\"dialog\"><div class=\"kb-gal-image-radius\"><div class=\"kb-gallery-image-contain kadence-blocks-gallery-intrinsic kb-gallery-image-ratio-land21 kb-has-image-ratio-land21\" ><img loading=\"lazy\" decoding=\"async\" src=\"data:image\/svg+xml,%3Csvg%20xmlns='http:\/\/www.w3.org\/2000\/svg'%20viewBox='0%200%201000%20667'%3E%3C\/svg%3E\"  data-splide-lazy=\"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-content\/uploads\/2026\/05\/SimpsonParadox-3-1.png\" width=\"1200\" height=\"600\" alt=\"\" data-full-image=\"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-content\/uploads\/2026\/05\/SimpsonParadox-3-1.png\" data-light-image=\"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-content\/uploads\/2026\/05\/SimpsonParadox-3-1.png\" data-id=\"3752\" class=\"wp-image-3752 skip-lazy\"\/><\/div><div class=\"kadence-blocks-gallery-item__caption\"><strong>Table 3. Sample with positive result in feline leukemia virus classified by sex with 932 animal samples<\/strong><\/div><\/div><\/a><\/figure><\/div><\/div><\/li><\/ul><\/div><\/div><\/div><\/div>\n\n<style>.wp-block-kadence-advancedheading.kt-adv-heading3742_543c4d-68, .wp-block-kadence-advancedheading.kt-adv-heading3742_543c4d-68[data-kb-block=\"kb-adv-heading3742_543c4d-68\"]{text-align:center;font-size:var(--global-kb-font-size-sm, 0.9rem);font-style:normal;}.wp-block-kadence-advancedheading.kt-adv-heading3742_543c4d-68 mark.kt-highlight, .wp-block-kadence-advancedheading.kt-adv-heading3742_543c4d-68[data-kb-block=\"kb-adv-heading3742_543c4d-68\"] mark.kt-highlight{font-style:normal;color:#f76a0c;-webkit-box-decoration-break:clone;box-decoration-break:clone;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.wp-block-kadence-advancedheading.kt-adv-heading3742_543c4d-68 img.kb-inline-image, .wp-block-kadence-advancedheading.kt-adv-heading3742_543c4d-68[data-kb-block=\"kb-adv-heading3742_543c4d-68\"] img.kb-inline-image{width:150px;vertical-align:baseline;}<\/style>\n<p class=\"kt-adv-heading3742_543c4d-68 wp-block-kadence-advancedheading\" data-kb-block=\"kb-adv-heading3742_543c4d-68\"><strong>Table 3. Sample with positive result in feline leukemia virus classified by sex with 932 animal samples<\/strong><br><em>[From MoZWE database]<\/em><\/p>\n<\/div><\/div>\n\n<\/div><\/div>\n\n<style>.wp-block-kadence-advancedheading.kt-adv-heading3742_921b55-91, .wp-block-kadence-advancedheading.kt-adv-heading3742_921b55-91[data-kb-block=\"kb-adv-heading3742_921b55-91\"]{font-style:normal;}.wp-block-kadence-advancedheading.kt-adv-heading3742_921b55-91 mark.kt-highlight, .wp-block-kadence-advancedheading.kt-adv-heading3742_921b55-91[data-kb-block=\"kb-adv-heading3742_921b55-91\"] mark.kt-highlight{font-style:normal;color:#f76a0c;-webkit-box-decoration-break:clone;box-decoration-break:clone;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.wp-block-kadence-advancedheading.kt-adv-heading3742_921b55-91 img.kb-inline-image, .wp-block-kadence-advancedheading.kt-adv-heading3742_921b55-91[data-kb-block=\"kb-adv-heading3742_921b55-91\"] img.kb-inline-image{width:150px;vertical-align:baseline;}<\/style>\n<p class=\"kt-adv-heading3742_921b55-91 wp-block-kadence-advancedheading\" data-kb-block=\"kb-adv-heading3742_921b55-91\">The results from the above information look like the incidence of FeLV in females was 38.5% (132\/343), whereas in males the incidence of FeLV was 34.5% (130\/377). According to such information, it appears that females are more likely to be infected than males.<\/p>\n\n\n<style>.wp-block-kadence-advancedheading.kt-adv-heading3742_75f93e-27, .wp-block-kadence-advancedheading.kt-adv-heading3742_75f93e-27[data-kb-block=\"kb-adv-heading3742_75f93e-27\"]{font-style:normal;}.wp-block-kadence-advancedheading.kt-adv-heading3742_75f93e-27 mark.kt-highlight, .wp-block-kadence-advancedheading.kt-adv-heading3742_75f93e-27[data-kb-block=\"kb-adv-heading3742_75f93e-27\"] mark.kt-highlight{font-style:normal;color:#f76a0c;-webkit-box-decoration-break:clone;box-decoration-break:clone;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.wp-block-kadence-advancedheading.kt-adv-heading3742_75f93e-27 img.kb-inline-image, .wp-block-kadence-advancedheading.kt-adv-heading3742_75f93e-27[data-kb-block=\"kb-adv-heading3742_75f93e-27\"] img.kb-inline-image{width:150px;vertical-align:baseline;}<\/style>\n<p class=\"kt-adv-heading3742_75f93e-27 wp-block-kadence-advancedheading\" data-kb-block=\"kb-adv-heading3742_75f93e-27\">In this case, we perform an in-depth analysis (Drill Down) to see what the real cause of the data is. To find latent variables by including<strong> Species <\/strong>in the variables.<\/p>\n\n\n<style>.kb-row-layout-id3742_590b43-f8 > .kt-row-column-wrap{align-content:start;}:where(.kb-row-layout-id3742_590b43-f8 > .kt-row-column-wrap) > .wp-block-kadence-column{justify-content:start;}.kb-row-layout-id3742_590b43-f8 > .kt-row-column-wrap{column-gap:var(--global-kb-gap-md, 2rem);row-gap:var(--global-kb-gap-md, 2rem);padding-top:var(--global-kb-spacing-sm, 1.5rem);padding-bottom:var(--global-kb-spacing-sm, 1.5rem);grid-template-columns:minmax(0, 1fr);}.kb-row-layout-id3742_590b43-f8 > .kt-row-layout-overlay{opacity:0.30;}@media all and (max-width: 1024px){.kb-row-layout-id3742_590b43-f8 > .kt-row-column-wrap{grid-template-columns:minmax(0, 1fr);}}@media all and (max-width: 767px){.kb-row-layout-id3742_590b43-f8 > .kt-row-column-wrap{grid-template-columns:minmax(0, 1fr);}}<\/style><div class=\"kb-row-layout-wrap kb-row-layout-id3742_590b43-f8 alignnone wp-block-kadence-rowlayout\"><div class=\"kt-row-column-wrap kt-has-1-columns kt-row-layout-equal kt-tab-layout-inherit kt-mobile-layout-row kt-row-valign-top\">\n<style>.kadence-column3742_36081b-c0 > .kt-inside-inner-col,.kadence-column3742_36081b-c0 > .kt-inside-inner-col:before{border-top-left-radius:0px;border-top-right-radius:0px;border-bottom-right-radius:0px;border-bottom-left-radius:0px;}.kadence-column3742_36081b-c0 > .kt-inside-inner-col{column-gap:var(--global-kb-gap-sm, 1rem);}.kadence-column3742_36081b-c0 > .kt-inside-inner-col{flex-direction:column;}.kadence-column3742_36081b-c0 > .kt-inside-inner-col > .aligncenter{width:100%;}.kadence-column3742_36081b-c0 > .kt-inside-inner-col:before{opacity:0.3;}.kadence-column3742_36081b-c0{position:relative;}@media all and (max-width: 1024px){.kadence-column3742_36081b-c0 > .kt-inside-inner-col{flex-direction:column;justify-content:center;}}@media all and (max-width: 767px){.kadence-column3742_36081b-c0 > .kt-inside-inner-col{flex-direction:column;justify-content:center;}}<\/style>\n<div class=\"wp-block-kadence-column kadence-column3742_36081b-c0\"><div class=\"kt-inside-inner-col\"><style>.kb-gallery-id-3742_d3bece-33 .kadence-blocks-gallery-item .kb-gal-image-radius, .kb-gallery-id-3742_d3bece-33 .kb-slide-item .kb-gal-image-radius img{border-radius:0px 0px 0px 0px;;}.kb-gallery-caption-style-bottom.kb-gallery-id-3742_d3bece-33 .kadence-blocks-gallery-item .kadence-blocks-gallery-item-inner .kadence-blocks-gallery-item__caption, .kb-gallery-caption-style-bottom-hover.kb-gallery-id-3742_d3bece-33 .kadence-blocks-gallery-item .kadence-blocks-gallery-item-inner .kadence-blocks-gallery-item__caption{background:linear-gradient(0deg, rgba(0, 0, 0, 0.8) 0, rgba(0, 0, 0, 0) 100%);}.kb-gallery-wrap-id-3742_d3bece-33.wp-block-kadence-advancedgallery{overflow:visible;}.kb-gallery-wrap-id-3742_d3bece-33.wp-block-kadence-advancedgallery .kt-blocks-carousel{overflow:visible;}<\/style><div class=\"kb-gallery-wrap-id-3742_d3bece-33 alignnone wp-block-kadence-advancedgallery\"><div class=\"kb-gallery-ul kb-gallery-non-static kb-gallery-type-slider kb-gallery-id-3742_d3bece-33 kb-gallery-caption-style-bottom-hover kb-gallery-filter-none kb-gallery-magnific-init\" data-image-filter=\"none\" data-lightbox-caption=\"true\"><div class=\"kt-blocks-carousel splide kt-carousel-container-dotstyle-dark kt-carousel-arrowstyle-none kt-carousel-dotstyle-dark kb-slider-group-arrow kb-slider-arrow-position-center\" data-slider-anim-speed=\"400\" data-slider-scroll=\"1\" data-slider-arrows=\"false\" data-slider-fade=\"true\" data-slider-dots=\"true\" data-slider-type=\"slider\" data-slider-hover-pause=\"false\" data-slider-auto=\"\" data-slider-speed=\"7000\" data-show-pause-button=\"false\"><div class=\"splide__track\"><ul class=\"kt-blocks-carousel-init kb-blocks-slider splide__list\"><li class=\"kb-slide-item kb-gallery-slide-item splide__slide\"><div class=\"kadence-blocks-gallery-item\"><div class=\"kadence-blocks-gallery-item-inner\"><figure class=\"kb-gallery-figure kb-gallery-item-has-link\"><a href=\"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-content\/uploads\/2026\/05\/SimpsonParadox-4-1.png\" class=\"kb-gallery-item-link\"   role=\"button\" aria-haspopup=\"dialog\"><div class=\"kb-gal-image-radius\"><div class=\"kb-gallery-image-contain kadence-blocks-gallery-intrinsic kb-gallery-image-ratio-land21 kb-has-image-ratio-land21\" ><img loading=\"lazy\" decoding=\"async\" src=\"data:image\/svg+xml,%3Csvg%20xmlns='http:\/\/www.w3.org\/2000\/svg'%20viewBox='0%200%201000%20667'%3E%3C\/svg%3E\"  data-splide-lazy=\"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-content\/uploads\/2026\/05\/SimpsonParadox-4-1.png\" width=\"1200\" height=\"600\" alt=\"\" data-full-image=\"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-content\/uploads\/2026\/05\/SimpsonParadox-4-1.png\" data-light-image=\"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-content\/uploads\/2026\/05\/SimpsonParadox-4-1.png\" data-id=\"3753\" class=\"wp-image-3753 skip-lazy\"\/><\/div><\/div><\/a><\/figure><\/div><\/div><\/li><\/ul><\/div><\/div><\/div><\/div>\n\n<style>.wp-block-kadence-advancedheading.kt-adv-heading3742_5fc718-f6, .wp-block-kadence-advancedheading.kt-adv-heading3742_5fc718-f6[data-kb-block=\"kb-adv-heading3742_5fc718-f6\"]{text-align:center;font-size:var(--global-kb-font-size-sm, 0.9rem);font-style:normal;}.wp-block-kadence-advancedheading.kt-adv-heading3742_5fc718-f6 mark.kt-highlight, .wp-block-kadence-advancedheading.kt-adv-heading3742_5fc718-f6[data-kb-block=\"kb-adv-heading3742_5fc718-f6\"] mark.kt-highlight{font-style:normal;color:#f76a0c;-webkit-box-decoration-break:clone;box-decoration-break:clone;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.wp-block-kadence-advancedheading.kt-adv-heading3742_5fc718-f6 img.kb-inline-image, .wp-block-kadence-advancedheading.kt-adv-heading3742_5fc718-f6[data-kb-block=\"kb-adv-heading3742_5fc718-f6\"] img.kb-inline-image{width:150px;vertical-align:baseline;}<\/style>\n<p class=\"kt-adv-heading3742_5fc718-f6 wp-block-kadence-advancedheading\" data-kb-block=\"kb-adv-heading3742_5fc718-f6\"><strong><strong>Table 4. Feline leukemia virus outcome is classified by species<\/strong><\/strong><br><em>[From MoZWE database]<\/em><\/p>\n<\/div><\/div>\n\n<\/div><\/div>\n\n<style>.wp-block-kadence-advancedheading.kt-adv-heading3742_9c8583-1b, .wp-block-kadence-advancedheading.kt-adv-heading3742_9c8583-1b[data-kb-block=\"kb-adv-heading3742_9c8583-1b\"]{font-style:normal;}.wp-block-kadence-advancedheading.kt-adv-heading3742_9c8583-1b mark.kt-highlight, .wp-block-kadence-advancedheading.kt-adv-heading3742_9c8583-1b[data-kb-block=\"kb-adv-heading3742_9c8583-1b\"] mark.kt-highlight{font-style:normal;color:#f76a0c;-webkit-box-decoration-break:clone;box-decoration-break:clone;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.wp-block-kadence-advancedheading.kt-adv-heading3742_9c8583-1b img.kb-inline-image, .wp-block-kadence-advancedheading.kt-adv-heading3742_9c8583-1b[data-kb-block=\"kb-adv-heading3742_9c8583-1b\"] img.kb-inline-image{width:150px;vertical-align:baseline;}<\/style>\n<p class=\"kt-adv-heading3742_9c8583-1b wp-block-kadence-advancedheading\" data-kb-block=\"kb-adv-heading3742_9c8583-1b\">When analyzing the age groups in the table above, it is found that the unspecified sex category has a higher infection rate than the other groups, and that <strong>male fishing cats have<\/strong> a higher infection rate than females. <\/p>\n\n\n<style>.wp-block-kadence-advancedheading.kt-adv-heading3742_d13c44-d2, .wp-block-kadence-advancedheading.kt-adv-heading3742_d13c44-d2[data-kb-block=\"kb-adv-heading3742_d13c44-d2\"]{font-style:normal;}.wp-block-kadence-advancedheading.kt-adv-heading3742_d13c44-d2 mark.kt-highlight, .wp-block-kadence-advancedheading.kt-adv-heading3742_d13c44-d2[data-kb-block=\"kb-adv-heading3742_d13c44-d2\"] mark.kt-highlight{font-style:normal;color:#f76a0c;-webkit-box-decoration-break:clone;box-decoration-break:clone;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.wp-block-kadence-advancedheading.kt-adv-heading3742_d13c44-d2 img.kb-inline-image, .wp-block-kadence-advancedheading.kt-adv-heading3742_d13c44-d2[data-kb-block=\"kb-adv-heading3742_d13c44-d2\"] img.kb-inline-image{width:150px;vertical-align:baseline;}<\/style>\n<p class=\"kt-adv-heading3742_d13c44-d2 wp-block-kadence-advancedheading\" data-kb-block=\"kb-adv-heading3742_d13c44-d2\">The results of the analysis are contrary to the conclusions when considering the overall.<br>The data discrepancy in this case happens due to sampling bias. This example shows how the way data is presented can be misleading. To avoid misinterpretation caused by Simpson\u2019s Paradox, data analysts should look for latent variables.<br><\/p>\n\n\n<style>.wp-block-kadence-spacer.kt-block-spacer-3742_8db060-f5 .kt-block-spacer{height:60px;}.wp-block-kadence-spacer.kt-block-spacer-3742_8db060-f5 .kt-divider{border-top-width:1px;height:1px;border-top-color:#eee;width:80%;border-top-style:solid;}<\/style>\n<div class=\"wp-block-kadence-spacer aligncenter kt-block-spacer-3742_8db060-f5\"><div class=\"kt-block-spacer kt-block-spacer-halign-center\"><hr class=\"kt-divider\"\/><\/div><\/div>\n\n\n<style>.wp-block-kadence-advancedheading.kt-adv-heading3742_a4aa7d-63, .wp-block-kadence-advancedheading.kt-adv-heading3742_a4aa7d-63[data-kb-block=\"kb-adv-heading3742_a4aa7d-63\"]{font-style:normal;}.wp-block-kadence-advancedheading.kt-adv-heading3742_a4aa7d-63 mark.kt-highlight, .wp-block-kadence-advancedheading.kt-adv-heading3742_a4aa7d-63[data-kb-block=\"kb-adv-heading3742_a4aa7d-63\"] mark.kt-highlight{font-style:normal;color:#f76a0c;-webkit-box-decoration-break:clone;box-decoration-break:clone;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.wp-block-kadence-advancedheading.kt-adv-heading3742_a4aa7d-63 img.kb-inline-image, .wp-block-kadence-advancedheading.kt-adv-heading3742_a4aa7d-63[data-kb-block=\"kb-adv-heading3742_a4aa7d-63\"] img.kb-inline-image{width:150px;vertical-align:baseline;}<\/style>\n<h2 class=\"kt-adv-heading3742_a4aa7d-63 wp-block-kadence-advancedheading\" data-kb-block=\"kb-adv-heading3742_a4aa7d-63\">References<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Appleton, D. R., French, J. M., &amp; Vanderpump, M. P. J. (1996). Ignoring a covariate: An example of Simpson&#8217;s paradox. The American Statistician, 50(4), 340-341. <a href=\"https:\/\/doi.org\/10.1080\/00031305.1996.10473563\">https:\/\/doi.org\/10.1080\/00031305.1996.10473563<\/a>\u00a0<\/li>\n\n\n\n<li><a href=\"https:\/\/plato.stanford.edu\/entries\/paradox-simpson\/\">Stanford Encyclopedia of Philosophy &#8211; Simpson\u2019s Paradox<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/bdi.or.th\/big-data-101\/simpsons-paradox\">Simpson\u2019s Paradox: \u0e15\u0e31\u0e27\u0e41\u0e1b\u0e23\u0e41\u0e1d\u0e07\u0e17\u0e35\u0e48\u0e40\u0e1b\u0e25\u0e35\u0e48\u0e22\u0e19\u0e41\u0e1b\u0e25\u0e07\u0e02\u0e49\u0e2d\u0e2a\u0e23\u0e38\u0e1b \u0e01\u0e31\u0e1a 2 \u0e01\u0e23\u0e13\u0e35\u0e15\u0e31\u0e27\u0e2d\u0e22\u0e48\u0e32\u0e07\u0e17\u0e35\u0e48\u0e19\u0e48\u0e32\u0e40\u0e2b\u0e25\u0e37\u0e2d\u0e40\u0e0a\u0e37\u0e48\u0e2d<\/a><\/li>\n<\/ul>\n\n\n<style>.wp-block-kadence-advancedheading.kt-adv-heading3742_60cd6b-a5, .wp-block-kadence-advancedheading.kt-adv-heading3742_60cd6b-a5[data-kb-block=\"kb-adv-heading3742_60cd6b-a5\"]{font-size:var(--global-kb-font-size-sm, 0.9rem);font-style:normal;}.wp-block-kadence-advancedheading.kt-adv-heading3742_60cd6b-a5 mark.kt-highlight, .wp-block-kadence-advancedheading.kt-adv-heading3742_60cd6b-a5[data-kb-block=\"kb-adv-heading3742_60cd6b-a5\"] mark.kt-highlight{font-style:normal;color:#f76a0c;-webkit-box-decoration-break:clone;box-decoration-break:clone;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.wp-block-kadence-advancedheading.kt-adv-heading3742_60cd6b-a5 img.kb-inline-image, .wp-block-kadence-advancedheading.kt-adv-heading3742_60cd6b-a5[data-kb-block=\"kb-adv-heading3742_60cd6b-a5\"] img.kb-inline-image{width:150px;vertical-align:baseline;}<\/style>\n<p class=\"kt-adv-heading3742_60cd6b-a5 wp-block-kadence-advancedheading\" data-kb-block=\"kb-adv-heading3742_60cd6b-a5\">Photo by <a href=\"https:\/\/unsplash.com\/@fr0ggy5?utm_source=unsplash&amp;utm_medium=referral&amp;utm_content=creditCopyText\">fr0ggy5<\/a> on <a href=\"https:\/\/unsplash.com\/photos\/a-close-up-of-a-cat-laying-on-a-bed-rOi9QNHl-1U?utm_source=unsplash&amp;utm_medium=referral&amp;utm_content=creditCopyText\">Unsplash<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>The classic example of a Simpson\u2019s paradox When analyzi [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":3754,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[134],"tags":[203,201],"class_list":["post-3742","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-disease-surveillance-en","tag-data-analysis","tag-statistic"],"acf":[],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-content\/uploads\/2026\/05\/fr0ggy5-rOi9QNHl-1U-unsplash.jpg","_links":{"self":[{"href":"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-json\/wp\/v2\/posts\/3742","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-json\/wp\/v2\/comments?post=3742"}],"version-history":[{"count":9,"href":"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-json\/wp\/v2\/posts\/3742\/revisions"}],"predecessor-version":[{"id":3809,"href":"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-json\/wp\/v2\/posts\/3742\/revisions\/3809"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-json\/wp\/v2\/media\/3754"}],"wp:attachment":[{"href":"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-json\/wp\/v2\/media?parent=3742"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-json\/wp\/v2\/categories?post=3742"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vs.mahidol.ac.th\/mozwe\/wp-json\/wp\/v2\/tags?post=3742"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}