{"id":2023,"date":"2012-04-09T16:42:10","date_gmt":"2012-04-09T15:42:10","guid":{"rendered":"https:\/\/www.zoeharcombe.com\/?p=2023"},"modified":"2018-10-18T11:01:43","modified_gmt":"2018-10-18T10:01:43","slug":"red-meat-mortality-the-usual-bad-science-part-2","status":"publish","type":"post","link":"https:\/\/www.zoeharcombe.com\/2012\/04\/red-meat-mortality-the-usual-bad-science-part-2\/","title":{"rendered":"Red meat & mortality & the usual bad science – Part 2"},"content":{"rendered":"

I blogged <\/a>on March 12 2012 about this press release <\/a>about an article in the\u00a0 Articles of Internal Medicine <\/a>published on the same day. The article now appears to be unavailable on free view.<\/p>\n

On March 20, I emailed the author listed for personal correspondence (frank.hu@channing.harvard.edu) with the following query:<\/p>\n

Dear Dr Hu
\nPlease can you help me understand how the multivariate analysis was done in your study (http:\/\/archinte.ama-assn.org\/cgi\/content\/full\/archinternmed.2011.2287<\/a>)?<\/p>\n

The raw data in table 1 shows the death rate falling – with Q2 and Q3 lower than Q1 in the HPFS and Q2, Q3 and Q4 lower than Q1 in the NHS. This is while exercise is falling and BMI, diabetes, smoking, calorie & alcohol intake were all increasing alongside red and processed meat consumption. I would have thought that once your multivariate analysis had allowed for these (and many other) variables to try to isolate meat consumption, the multivariate index would be substantially lower than my death rate line, which includes these risk factors. As a comparison, if I index my death rate for the HPFS is would be 1.00; 93.43; 97.70; 103.97 and 124.26 (doing the same 1.00 base line thing) vs. the multivariate index of 1.00; 1.12; 1.21; 1.25 and 1.37.<\/p>\n

Many thanks
\nKind regards – Zoe<\/p>\n

—————<\/p>\n

I received\u00a0 a prompt reply later that day:<\/p>\n

Zoe,<\/p>\n

Thanks for your interest in our paper. Unfortunately, the crude mortality rate is misleading because the mean age in the first quintile (Q1)\u00a0was older than other quintiles. Therefore, the crude mortality rate in the first quintile would be artificially higher than other quintiles. In this analysis, age was a stronger confounding factor than other lifestyle factors.<\/div>\n

\n<\/span><\/div>\n
Hope this helps.<\/span><\/div>\n

\n<\/span><\/div>\n

Frank Hu<\/span><\/p>\n

—————<\/p>\n

I emailed back on 22 March:<\/p>\n

Many thanks for the prompt reply. Aside from thinking that “Age is the main risk factor in mortality” would have been a better headline, I’m still puzzled. Please can you help with the following:<\/p>\n

1) Table 1 says it is age standardised – what does this mean? (*)<\/p>\n

2) The ages in Table 1 are 53.8, 52.6, 52.5, 52.5 and 52.2 for Q1 to Q5 respectively for the HPFS and 47.3. 46, 45.8, 45.3 and 46 for the NHS. Not withstanding query 1, how could such small differences have had such an impact on the study a) per se and b) to the extent that “age was a stronger confounding factor than other lifestyle factors” when exercise was down by over a third, BMI up from normal to overweight, smoking almost three times higher in Q5 than Q1, incidence of diabetes almost doubled, alcohol intake up 60% and calorie intake over 40% higher (all figs for the HPFS – the NHS has different numbers, same trends) and that’s even before we look at meat consumption.<\/p>\n

3) The death rates that I calculated were from Table 2 – notwithstanding query 1. Hence as total red meat, ‘unprocessed’ red meat (hamburgers?!) and processed red meat all rose from Q1 through to Q5, so the death rates in the HPFS are lower in Q2 and Q3 than Q1 and the death rates in the NHS are lower in Q2, Q3 and Q4 than Q1. Even if Q1 is supposed to be ignored for some strange reason, the Q3 death rate is still lower than Q2 in all meat categories in the NHS and for the ‘unprocessed’ meat category in the HPFS i.e. deaths fall as these groups of meat consumption rise.<\/p>\n

4) If I ‘index’ the death rates, as has been done in the multivariate study, the death rate ‘index’ for the HPFS and the NHS are as follows – with the total meat multivariate index alongside. I would expect all the above mentioned factors (reduced activity, increased BMI, increased smoking, increased diabetes, increased alcohol and increased calorie intake from Q1 to Q5) to be impacting death rates so that they also rise from Q1 to Q5. a) they don’t and b) how can the multivariate line have allowed for all of these and yet rise consistently as it does?<\/p>\n\n\n\n\n<\/colgroup>\n\n\n\n\n\n\n\n\n
HPFS<\/td>\n<\/td>\nQ1<\/td>\nQ2<\/td>\nQ3<\/td>\nQ4<\/td>\nQ5<\/td>\n<\/tr>\n
<\/td>\nDeath rate as index<\/td>\n1.00<\/td>\n0.93<\/td>\n0.98<\/td>\n1.04<\/td>\n1.24<\/td>\n<\/tr>\n
Total meat<\/td>\nMultivariate<\/td>\n1.00<\/td>\n1.12<\/td>\n1.21<\/td>\n1.25<\/td>\n1.37<\/td>\n<\/tr>\n
<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
Nurses<\/td>\n<\/td>\nQ1<\/td>\nQ2<\/td>\nQ3<\/td>\nQ4<\/td>\nQ5<\/td>\n<\/tr>\n
<\/td>\nDeath rate as index<\/td>\n1.00<\/td>\n0.93<\/td>\n0.90<\/td>\n0.97<\/td>\n1.27<\/td>\n<\/tr>\n
Total meat<\/td>\nMultivariate<\/td>\n1.00<\/td>\n1.08<\/td>\n1.11<\/td>\n1.18<\/td>\n1.24<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Many thanks
\nKind regards – Zoe<\/p>\n

(*) the reason for asking this question was not because I don’t know what “age standardised” means but to flush out why the reply from Frank Hu was effectively that the data is misleading because of age and yet the table claims to have been age standardised<\/p>\n

—————<\/p>\n

I received no reply.<\/p>\n

On 3 April I resent the unanswered email:<\/p>\n

Dear Frank
\nPlease are you able to reply to this?
\nMany thanks
\nKind regards – Zoe<\/p>\n

I received no reply.<\/p>\n

I’ll update this post with any response that Frank Hu makes.<\/p>\n","protected":false},"excerpt":{"rendered":"

I blogged on March 12 2012 about this press release about an article in the\u00a0 Articles of Internal Medicine published<\/p>\n","protected":false},"author":2,"featured_media":4661,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1057,1068,1071,1083],"tags":[581,582,414,413,576,575,577],"_links":{"self":[{"href":"https:\/\/www.zoeharcombe.com\/wp-json\/wp\/v2\/posts\/2023"}],"collection":[{"href":"https:\/\/www.zoeharcombe.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.zoeharcombe.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.zoeharcombe.com\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.zoeharcombe.com\/wp-json\/wp\/v2\/comments?post=2023"}],"version-history":[{"count":8,"href":"https:\/\/www.zoeharcombe.com\/wp-json\/wp\/v2\/posts\/2023\/revisions"}],"predecessor-version":[{"id":4771,"href":"https:\/\/www.zoeharcombe.com\/wp-json\/wp\/v2\/posts\/2023\/revisions\/4771"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.zoeharcombe.com\/wp-json\/wp\/v2\/media\/4661"}],"wp:attachment":[{"href":"https:\/\/www.zoeharcombe.com\/wp-json\/wp\/v2\/media?parent=2023"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.zoeharcombe.com\/wp-json\/wp\/v2\/categories?post=2023"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.zoeharcombe.com\/wp-json\/wp\/v2\/tags?post=2023"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}