Evaluating periodic multiphasic health checkups: A controlled trial

Abstract

In 1964 a controlled trial was initiated to evaluate the effectiveness of a program of urging subjects to take periodic multiphasic health checkups (MHC's) in preventing or postponing morbidity, disability, and mortality. A group of over 5000 Kaiser Foundation Health Plan members aged 35–54 at entry to the study has been urged to take MHC's annually. Along with a comparable group of members not so urged, these subjects have been followed for 11 years. Use of outpatient clinic services, other than those services forming part of the MHC was similar in the urged (study) group and in non-urged (control) group. Overall, hospital use was also similar in the two groups. There was no difference between the overall groups in self-reported disability. However, selfreported disability was significantly less common in the older study group men (aged 45–54 at entry), largely due to less disability from hypertension complications, ischemic heart disease, and back conditions. This provides a hypothesis as to a beneficial effect in a specific age-sex group that should be tested further. Mortality from a set of conditions hypothesized in advance to be most postponable or preventable through periodic MHC's was significantly lower in the study group as a whole, primarily due to fewer deaths from hypertension complications and colorectal cancer. On the other hand, suicides and lympho-hematopoietic cancer deaths were significantly more common in the study group, though reanalysis of the data revealed little relationship between these latter death rates and actual MHC exposure. Total mortality, from all causes combined, was slightly lower in the study group, but this difference was not statistically significant. Though the prevalence of a number of disability and mortality risk factors was somewhat higher in the control group at entry, adjustment for these differences did not eliminate the statistically significant control group excesses in disability (older men only) and potentially postponable cause mortality. With regard to processes by which increased study group MHC exposure may have caused the observed health outcome differences, there was more identification and treatment of hypertension, hyperlipidemia, cigarette smoking, obesity, and diabetes in the study group, though the differences were not large. There also was a trend toward earlier diagnoses of colorectal cancer in the study group, due mostly to MHC-related sigmoidoscopy. When the economic impact of all major health-related events was estimated for the older men in the 1965–1975 period, there was a net difference of over $2100 per man, favoring the study group. The health outcome rates for the women and the younger men indicated that there would be no savings for these other study group subjects, were similar cost analyses to be made.