BACKGROUND:

Three of the CDP treatments (two doses of estrogen and dextrothyroxine) were stopped prematurely because of toxicity. At the time the treatments were stopped, it was thought that future assessment of the status of patients on those treatments would be important to evaluate long-term sequellae. Another clinical trial evaluating clofibrate for primary prevention found that more patients on that treatment than on placebo had died. This effect persisted even after the treatment was stopped. Therefore, it was considered necessary to follow the CDP patients on clofibrate.

Of the original 834l patients, about 6000 were still alive in March l975. Cause-specific mortality in those patients was assessed through March l980.

DESIGN NARRATIVE:

The vital status of the subjects known to be alive at the end of the CDP in March l975 was assessed as of March l980. This was accomplished through questioning the local investigators, letters to the subjects, and by use of Social Security Administration and National Death Index records.