Ninety nine of 830 articles met the inclusion criteria for detailed data abstraction (). Sixty one were randomised controlled trials that included outcomes on falls. These were reviewed for potential inclusion in the meta-regression analyses. After excluding articles for being outside our specified follow up period, using idiosyncratic interventions that could not be pooled (for example, restraints, a bed alarm), or including duplicate study populations (see bmj.com
), 40 trials contributed data to the meta-analyses (see table A on bmj.com
). Using the Jadad tool for study quality (scores from 0 to 5), four trials scored 1, 22 scored 2, and 14 scored 3.12
As this scoring system gives up to two points for double blinding, and double blinding is not conceptually possible for falls intervention studies, the maximum possible score for these studies is effectively 3. Nine studies described concealment of intervention allocation.
Flowchart of articles
Data for the meta-analysis of participants who fell at least once came from 26 intervention groups in 22 studies. The combined data showed a significant reduction in the risk of falling (risk ratio 0.88, 95% confidence interval 0.82 to 0.95; P = 0.03; I2 = 31%, 95% uncertainty interval, 0% to 61%; ). Data for the meta-analysis on monthly rate of falling came from 30 intervention groups in 27 studies. The combined data showed a significant reduction in the monthly rate of falling (incidence rate ratio 0.80, 0.72 to 0.88; P < 0.001; I2 = 81%, 74% to 86%; ).
Pooled risk ratio of participants who fell at least once
Pooled incidence rate ratio of monthly rate of falling
None of the studies directly assessed the relative effectiveness of intervention components. To assess such effectiveness we therefore compared the magnitude of the effect of each of the components to a control group that received usual care. We entered all studies in the meta-regression model that assessed the effect of individual components while controlling for other components (). A multifactorial falls risk assessment and management programme had a statistically significant beneficial effect on both risk of falling (adjusted risk ratio 0.82, 0.72 to 0.94) and monthly rate of falling (adjusted incidence rate ratio 0.63, 0.49 to 0.83). The two models fit relatively well, explaining 29% and 16% of the variance, respectively. The risks assessed in multifactorial risk assessments varied among studies. The most commonly assessed risks were drugs, vision, environmental hazards, and orthostatic blood pressure (). Exercise was an intervention in the largest number of studies. This also had a statistically significant beneficial effect on the risk of falls (adjusted risk ratio 0.86, 0.75 to 0.99), but on monthly rate of falling (adjusted incidence rate ratio 0.86, 0.73 to 1.01) did not reach conventional statistical significance. Environmental modification and education were primary components of a few studies, and the pooled estimates were not statistically significant.
Meta-regression estimates of effect of individual intervention components controlling for other intervention components
Components of multifactorial falls risk assessment
In the second meta-regression analysis, we were not able to detect statistically significant differences or consistent trends in the efficacy between different types of exercises (). Colinearity between balance and both flexibility and strength was problematic.
Meta-regression estimates of effect of individual exercise components controlling for other exercise components
We observed some trends in the relative effectiveness of the major components of a multifactorial falls risk assessment and management programme, but no component was most or least effective.
In a post hoc analysis we attempted to see if the greater effectiveness of the multifactorial falls risk assessment and management programme was due to the preferential enrolment of people at higher risk. Therefore we classified each study according to population (general, community dwelling, or higher than average risk groups for falls—for example, living in a nursing home, recent history of falls) and repeated our meta-regression analyses stratified by population. No significant differences were found in effectiveness of the interventions by population studied.
A visual inspection of the funnel plots indicated no evidence of publication bias for all studies included in the meta-analyses for the risk ratio of falling at least once and for the falls incidence rate ratio. Although the adjusted rank correlation test indicated no evidence of publication bias, the regression asymmetry test did indicate some evidence for the falling at least once outcome.
None of the sensitivity analyses significantly changed the estimates of the meta-regression models, nor did the additional meta-regression models yield contrary conclusions.