{"id":864,"date":"2020-11-24T09:36:40","date_gmt":"2020-11-24T14:36:40","guid":{"rendered":"https:\/\/covidqanda.org\/?p=864"},"modified":"2020-11-24T09:36:40","modified_gmt":"2020-11-24T14:36:40","slug":"what-is-age-adjustment","status":"publish","type":"post","link":"https:\/\/covidqanda.org\/?p=864","title":{"rendered":"What is age-adjustment?"},"content":{"rendered":"\n

Question:<\/span><\/strong>\u00a0I keep reading news articles like this one<\/a>\u00a0that mention “age-adjustment” as related to racial\/ethnic differences in COVID hospitalization rates, death rates, etc.\u00a0 I’m not sure that I actually understand what “age-adjustment” is.\u00a0 Would you explain?\u00a0<\/p>\n\n\n\n

Answer:<\/span><\/strong>\u00a0Age-adjustment is a process researchers use to try and make apples-to-apples comparisons between diverse populations.\u00a0 In the United States, the age structure of each racial\/ethnic group is quite different (Figure 1<\/strong>).\u00a0 If you want to make comparisons across racial\/ethnic groups for outcomes that vary by age– like disease prevalence or mortality– you have to take population composition (age distribution) into account.\u00a0 Enter age-adjustment.\u00a0\u00a0<\/p>\n\n\n\n


Age-adjustment can be direct or indirect<\/a>, but for brevity and context I’m going to describe the basic concept<\/a>\u00a0of direct age-adjustment (also called direct standardization).\u00a0 Direct standardization is the process of applying age-specific rates (of disease\/death\/etc.) from our population of interest to a standard population.\u00a0 That may still sound confusing, but believe me, it’s not!\u00a0 Let me further explain using an example from our recent analysis of racial\/ethnic disparities in COVID case fatality rates<\/a>\u00a0(Figure 2<\/strong>).\u00a0 Reminder: case fatality rates are the proportion\u00a0of cases that result in death.\u00a0
<\/p>\n\n\n\n

On the left side of Figure 2<\/strong>, you’ll see monthly crude case fatality rates by race.\u00a0 On the right side, you’ll see the same rates after age-adjustment.\u00a0 Strikingly different, right?!<\/strong>\u00a0 That’s because the left side– the crude rate– is misleading.\u00a0 Without age-adjustment, the differences between racial\/ethnic groups are being driven by population composition, NOT actual disease outcomes.\u00a0 The right side shows the real case fatality differences between racial\/ethnic groups. To arrive at the age-standardized rate visualized on the right, we first measured case fatality rates for each 10-year age\/race group.\u00a0 We then applied these rates to a standard population– here, all COVID cases in the US.\u00a0 As recently as August, Blacks were still dying of COVID-19 at 1.24x the rate of whites.\u00a0 Age-adjusted case fatality rates\u00a0reveal dramatically different racial and ethnic disparities that are hidden by crude case fatality rates. Such adjustment is imperative for understanding COVID-19\u2019s toll.<\/p>\n\n\n\n


Figure 1. Population pyramids, Hispanics and non-Hispanic Whites, 2013 (<\/strong>from Pew Research Center<\/a>)<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Figure 2. Crude and age-adjusted COVID-19 Case Fatality Rates by Race, March-August<\/strong>\u00a0(from Fabic, Choi, Bishai<\/a>)<\/p>\n\n\n\n

\"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

Question:\u00a0I keep reading news articles like this one\u00a0that mention “age-adjustment” as related to racial\/ethnic differences in COVID hospitalization rates, death rates, etc.\u00a0 I’m not sure that I actually understand what “age-adjustment” is.\u00a0 Would you explain?\u00a0 Answer:\u00a0Age-adjustment is a process researchers use to try and make apples-to-apples comparisons between diverse populations.\u00a0 In the United States, the […]<\/p>\n","protected":false},"author":1,"featured_media":866,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"nf_dc_page":"","om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":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":[93,22],"tags":[105],"class_list":["post-864","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-models","category-mortality","tag-race","fallback-thumbnail"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"https:\/\/i0.wp.com\/covidqanda.org\/wp-content\/uploads\/2020\/11\/image-9.png?fit=624%2C624&ssl=1","_links":{"self":[{"href":"https:\/\/covidqanda.org\/index.php?rest_route=\/wp\/v2\/posts\/864","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/covidqanda.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/covidqanda.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/covidqanda.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/covidqanda.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=864"}],"version-history":[{"count":1,"href":"https:\/\/covidqanda.org\/index.php?rest_route=\/wp\/v2\/posts\/864\/revisions"}],"predecessor-version":[{"id":867,"href":"https:\/\/covidqanda.org\/index.php?rest_route=\/wp\/v2\/posts\/864\/revisions\/867"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/covidqanda.org\/index.php?rest_route=\/wp\/v2\/media\/866"}],"wp:attachment":[{"href":"https:\/\/covidqanda.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=864"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/covidqanda.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=864"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/covidqanda.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=864"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}