Non-pharmacological interventions for caregivers ... - Update Software

We also checked the reference lists of relevant articles and contacted
authors and researchers to identify other potentially relevant
studies. We searched for trials in all languages and arranged
translation of relevant studies published in languages other then
English.
Data collection and analysis
Selection of studies
One review author (LL) screened all the titles, abstracts and keywords
of publications identified by the searches to assess their eligibility.
At this stage, we excluded studies that clearly did not
meet the inclusion criteria. We obtained a paper copy of the full
publication for every study that was potentially relevant. LL and
one other review author (PL, TQ or FM) applied the selection
criteria to each study identified by the search strategy. We resolved
disagreements by consensus.
Data extraction and management
We sought published and unpublished data for this review. Two
review authors independently extracted the data using a standard
data recording form (LL, TQ or FM). The features of interest in
parallel trials were sequence generation, allocation sequence concealment,
blinding, incomplete outcome data, selective outcome
reporting and other potential sources of bias. All review authors
(TQ, PL, LN, DS, FM and JT) participated in a blinded assessment
of trial methods using The Cochrane Collaboration’s tool
for assessing risk of bias (Higgins 2008). We determined each trial
to be at ’high risk, ’low risk’ or ’unclear risk’ of bias. We resolved
disagreements by discussion.
Assessment of risk of bias in included studies
For each included trial we extracted information about the method
of randomisation and allocation concealment, blinding of outcome
assessment, whether all the randomised patients were accounted
for in the analysis and the presence of selective outcome
reporting.
Measures of treatment effect
Continuous outcomes
All outcomes within this review, with the exception of mortality,
are continuous outcomes. However, for the purposes of the review,
we analysed only informal caregiver stress and strain, informal
caregiver well-being (the primary outcomes), depression, healthrelated
quality of life and satisfaction (secondary outcomes) as
Non-pharmacological interventions for caregivers of stroke survivors (Review)
Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
continuous variables, using means and standard deviations, under
the assumption that the data have a normal distribution.
Dichotomous outcomes
This review also includes dichotomous data, that is data from
outcomes that can be split into two discrete categories; each trial
participant must be in one state or the other, and cannot be in both
categories. There are two types of dichotomous outcomes in this
review: dichotomous data (alive or dead) and data that have been
dichotomised from outcomes that are not truly dichotomous. For
the purposes of this review the psychometric measures of stress or
distress, depression and measures of anxiety have been converted
to dichotomous data using published optimal clinical cut-points.
The optimal cut-point is a value in an ordered sequence of values
that is used to separate those individuals who are in one state versus
another state. For example, those participants who lie above the
clinical cut-point on a depression scale are likely to meet mood
disorder diagnostic criteria for depression and those who lie below
the cut-point are unlikely to be distressed. The effect measure of
choice for dichotomous outcomes was the risk ratio (RR).
Unit of analysis issues
The focus of this review was on trials that randomised individual
caregivers or caregiver and stroke survivor dyads. In the event we
had included a trial using a cluster design (in which participants
were randomised at group level) we would have used the intracluster
correlation coefficient (ICC) to estimate the effective sample
size.
Dealing with missing data
This review focused on trials that have randomised individual caregivers
or caregiver and stroke survivor dyads. The primary aim of
this review was to obtain standardised data through collaboration
with the original trialists. Where data were missing from a published
report we contacted the primary investigators in an attempt
to get this information. Incomplete data are relatively common in
trials of rehabilitation. It is difficult to impute missing values for
continuous outcomes.
Assessment of heterogeneity
We assessed heterogeneity by visually examining forest plots, by
performing the Chi 2 test using a P value of less than 0.1 to indicate
heterogeneity. We used a P value of less than 0.1 rather than the
conventional cut-point of 0.05 because of the low power of this
test. We quantified the effect of heterogeneity using the I 2 statistic
including its 95% confidence interval (CI). The I 2 statistic is a
measure of the degree of inconsistency in the studies’ results. The
value of the I 2 statistic ranges from 0% to 100% with 0% representing
no observed heterogeneity to larger number representing
5