O. Paul et al., MULTIPLE RISK FACTOR INTERVENTION TRIAL - RISK FACTOR CHANGES AND MORTALITY RESULTS (REPRINTED FROM JAMA, VOL 248, PG 1465-1477, 1982), JAMA, the journal of the American Medical Association, 277(7), 1997, pp. 582-594
The Multiple Risk Factor Intervention Trial was a randomized primary p
revention trial to test the effect of a multifactor intervention progr
am on mortality from coronary heart disease (CHD) in 12,866 high-risk
men aged 35 to 57 years. Men were randomly assigned either to a specia
l intervention (SI) program consisting of stepped-care treatment for h
ypertension, counseling for cigarette smoking, and dietary advice for
lowering blood cholesterol levels, or to their usual sources of health
care in the community (UC). Over an average follow-up period of seven
years, risk factor levels declined in both groups but to a greater de
gree for the SI men. Mortality from CHD was 17.9 deaths per 1,000 in t
he SI group and 19.3 per 1,000 In the UC group, a statistically nonsig
nificant difference of 7.1% (90% confidence interval, -15% to 25%). To
tal mortality rates were 41.2 per 1,000 (SI) and 40.4 per 1,000 (UC).
Three possible explanations for these findings are considered: (1) the
overall intervention program, under these circumstances, does not aff
ect CHD mortality; (2) the intervention used does affect CHD mortality
, but the benefit was not observed in this trial of seven years' avera
ge duration, with lower-than-expected mortality and with considerable
risk factor change in the UC group; and (3) measures to reduce cigaret
te smoking and to lower blood cholesterol levels may have reduced CHD
mortality within subgroups of the SI cohort, with a possibly unfavorab
le response to antihypertensive drug therapy in certain but not all hy
pertensive subjects. This last possibility was considered most likely,
needs further investigation, and lends support to some preventive mea
sures while requiring reassessment of others.