Objective
Determine the impact of build on insurance applicant mortality accounting for smoking, laboratory test values and blood pressure.
Method
The study consisted of 2,051,370 applicants tested at Clinical Reference Laboratory between 1993 and 2007 with build and cotinine measurements available whose body mass index (BMI) was between 15 and 47. Vital status was determined as of September, 2011 by the Social Security Death Master File. Excluded from the primary study were applicants with HbA1c values ≥6.5%, systolic BP ≥141 mmHg, albumin values ≤3.3 g/dL or total cholesterol values ≤130 mg/dL. Relative mortality was determined by Cox regression analysis for bands of BMI split by age, sex and smoking status (urine cotinine positive).
Results
A majority of applicants had BMI >24 (overweight or obese by WHO criteria). After the exclusions noted above, relative mortality does not increase by >34% unless BMI is <20 (<18 for female non-smokers age 18 to 59) or BMI is >34. BMI values in the range of 22 to 24 and 25 to 29, overall, had similar and the lowest relative risks. For most nonsmokers, risk was lowest in the lower of these two BMI bands but for smokers (and non-smoking males age 60 to 89) risk was lowest in the higher BMI band.
Additional analysis showed limited reduction in relative risk by accounting for all laboratory test values as well as continuing the exclusions. Eliminating the exclusions resulted in only a modest increase in relative risk because the mortality rate of the reference band increased as well.
Conclusion
After excluding elevated HbA1c and blood pressure (associated with high BMI) and low albumin and cholesterol (associated with low BMI) which are usually evaluated separately, mortality varies by a limited degree for BMI 20 to 34. Accounting for the mortality impact of other test values, in addition to the exclusions noted, reduced mortality associated with high BMI to a limited extent, but had little impact on mortality associated with low BMI.
The Impact of Continuous Improvement of Laboratory Test Result Comments on Requests for Consultation
