In 16 studies patients were asked if they found electroconvulsive therapy
helpful and in 12 studies they were asked if they would have the treatment
again (). The level of
positive responses varied widely between studies (tests for heterogeneity:
χ2=370, P < 0.001, for treatment helpful,
χ2=256, P < 0.001 for would have treatment again). The
Forrest plot for “helpful” shows that the patient led and
collaborative studies report the lowest levels of positive responses; there
was, however, an overlap in the confidence intervals
( and
).
| Table 1Details of perceived benefit of electroconvulsive therapy, date, sample
size, and four scored methodological variables of studies eliciting patients'
views on treatment. Values are numbers (percentages; 95% confidence intervals)
of patients unless (more ...) |
A funnel plot showed no evidence of publication bias among the clinical
studies. No systematic relation was found between perceived benefit and the
country, or region of the United Kingdom, where the research was
undertaken.
Methodological variables
The number of questions, complexity of the interviews, and the interval
before interview were intercorrelated (between number of questions and both
the other two variables r=0.54, between interval and complexity r=0.75). The
clinical studies tended to use fewer questions, less complex schedules, and a
shorter interval, although the difference in complexity was not significant
(see ).
Studies where the interviews were conducted soon after treatment, in
hospital settings, by the treating doctor, were more likely to report positive
views of electroconvulsive therapy (). Studies with low complexity schedules, few questions, and a
short interval were also associated with high perceived benefit. In the case
of treatment considered helpful there was a clear hierarchy in setting, as
coded from studies of inpatients (coded 1) to studies based in the community
(coded 5).
| Table 2Associations between positive responses and methodological variables of
patients' responses to electroconvulsive therapy. Values are odds ratios (95%
confidence intervals) unless stated otherwise |
When the analyses were repeated for the clinical studies alone, the effects
were in the same direction and of a similar magnitude. Because of reduced
sample sizes, fewer associations were significant. Within clinical studies,
the number of questions remained significantly associated with treatment
considered helpful, and complexity and interval were associated with whether
the patient would have treatment again. In multivariate models, only setting
remained significant.
Persistent memory loss
Of the 35 studies, 20 considered memory loss as a consequence of
electroconvulsive therapy. Thirteen were excluded because data were not given
or the interval between treatment and questions about memory loss was less
than six months. In four of the remaining studies, respondents were asked
specifically whether they had experienced persistent or permanent memory loss,
and in four studies any reported memory problem was sought (one study reported
on both; ).
| Table 3Numbers (percentages) of patients reporting memory loss, by study |
The rate of reported persistent memory loss varied between 29% and 55%,
but, unlike levels of perceived benefit, the rate did not seem to depend on
whether studies were clinical or patient based, with relatively high levels
being reported by both types of study.