acknowledges that changes in symptoms may occur following a placebo drug, but
regards these as less important than the real changes that occur following the real drug.
However, in 1982, data from the Coronary Drug Project was published which suggested
that the best predictor of mortality in men who had survived a heart attack was not
taking the lipid-lowering drug compared with taking the placebo drug, but adherence to
taking any drug at all (whether an active drug or a placebo drug). The results indicated
that adherers had lower mortality at five years than the non-adherers in both the
experimental and the placebo groups. Horwitz et al. (1990) set out to examine whether
adherence was a good predictor of risk of death in a large Beta-Blocker Heart Attack
Trial (BHAT 1982) and to evaluate whether any effects of adherence could be explained
by social and behavioural characteristics (e.g. were the non-adherers also the smokers
with stressful lives?).Methodology
Horwitz et al. reported a reanalysis of the data collected as part of the Beta-Blocker Heart
Attack Trial, which was a multi-centre, randomized, double-blind trial comparing pro-
prandol (a beta-blocker) with a placebo drug in patients who had survived an acute heart
attack (this is known as secondary data analysis).Subjects The original study included 3837 men and women aged 30–69 years who
were reassessed every three months for an average of 25 months. The data from 1082
men in the experimental condition (who had received the beta-blocker) and 1094 men in
the placebo condition were analysed (all women and those men who had not completed
the psychosocial measures were excluded from the analysis). Follow-up data was
analysed for 12 months.Design The study was prospective with subjects completing initial measures six weeks
after hospital discharge and completing subsequent follow-up measures every three
months.Measures Measures were taken of (1) psychosocial factors, (2) adherence and (3)
clinical characteristics: Psychosocial factors. The subjects completed a structured interview six weeks
after discharge. The answers to this were grouped to form four psychosocial
variables: levels of life stress, social isolation, depression and type A behaviour
pattern. In addition, data were collected concerning their health practices both at
baseline and at follow-up (e.g. smoking, alcohol use, diet, physical activity other than
work).
Adherence. For each follow-up interval (three months) adherence was calculated as
the amount of medication divided by the amount prescribed. The subjects were divided
into poor adherers (taking less than or equal to 75 per cent of prescribed medication)
and good adherers (taking more than 75 per cent of prescribed medication).PLACEBOS AND THE INTERRELATIONSHIP BETWEEN BELIEFS, BEHAVIOUR AND HEALTH 317