Mortality study of policies on insured lives with diabetes mellitus known at time of issue.
BACKGROUND: This is an Impairment Study Capture System (ISCS) study of contemporary diabetes mellitus mortality among insured lives. Because the diagnosis and treatment of diabetes has changed during the last 15 years, many applicants may be expected to exhibit more favorable outcomes than in the past. The study covers policy-years durational experience extending to only 10 years. METHODS: We analyzed the total mortality experience of 41,972 insurance policies. The policies were issued at standard or substandard premium rates between 1989 and 2002 policy anniversaries. The number of policies terminated by death (actual deaths) is compared with expected deaths using the 2001 Valuation Basic Table (2001 VBT). Main outcome measures are expressed as mortality ratios (MR %) and excess death rates/1000 (EDR/M). Poisson confidence intervals are used to test the statistical significance of mortality ratios at the 95% confidence limit. RESULTS: The total experience is based on 103,104 policy-years exposure: males 57,888 policy-years (56%) and females 45,216 policy-years (44%). There were 495 policy-deaths 284 male and 211 female. Substandard risks represented the majority of the total exposure, 76,658 policy-years in both sexes combined (male 56%, female 44%). The mean duration of substandard exposure was 2.3 years. Total mortality for all insured age-groups and risk categories combined was 187%. The mortality ratios for policies rated standard had confidence intervals that were consistent with 100% of the 2001 VBT. The mortality ratios for policies rated substandard had confidence intervals that were above 100% of the 2001 VBT. Mortality ratios varied with the type of treatment. They were lowest in those treated with diet alone and highest in individuals treated with diet plus insulin. CONCLUSION: A clinical diagnosis of diabetes continues to demonstrate evidence of increased, but improving, mortality in insured individuals. The underwriting risk appraisal process effectively categorizes the risk, especially for the substandard classes where the ratings assigned to policies were consistent with the mortality results. The lack of significant differences in the mortality ratios between males and females as well as between nonsmokers and smokers indicate that the early duration variations by gender and smoking status in the 2001 VBT account for these differences in early duration diabetes mortality. Subsequent follow-up studies containing longer durations may show these differences emerging. Results must be interpreted with caution because of the small data set, limited number of ISCS participating companies, and durational experience extending to only 10 policy years.