Incidence and prevalence of falls in adults with intellectual disability living in the community: a systematic review

Objective: The objective of the review was too synthesize the best available evidence on the incidence and prevalence of falls among adults with intellectual disability (ID). Introduction: Falls among adults with ID frequently cause physical injury and may negatively impact on their quality of life. Studies investigating falls among people with ID have used differing methods and populations, making it difficult to determine the scope and extent of this problem. Inclusion criteria: This review considered all studies that included adults with ID aged 18 years and over and which reported percentage/numbers of individuals who fell, and the total number of falls and injurious falls sustained from a fall. Studies were included if they were conducted within community or residential settings. Studies that were conducted in hospitals were excluded. Cohort studies, case-control and cross-sectional studies were included. Studies that used an experimental design, both randomized controlled and quasi experimental design, were also included. Methods: A three-step search strategy was undertaken for published and unpublished literature in English from 1990 to 2017. An initial search of MEDLINE and CINAHL was undertaken before a more extensive search was conducted using keywords and index terms across 11 electronic databases. Two independent reviewers assessed the methodological quality of the included studies using the Joanna Briggs Institute standardized critical appraisal instrument for prevalence studies (Joanna Briggs Institute Critical Appraisal Checklist for Studies Reporting Prevalence Data). Data was extracted using the Joanna Briggs Institute's standardized extraction tool. Data that directly reported or could be used to calculate the incidence and prevalence of falls were extracted. Quantitative data for the number (proportion) of people who fell were pooled in statistical meta-analysis using STATA version 14 (Stata Corp LLC, Texas, USA). Data measuring incidence of falls (rate of falls for the duration of the study) and incidence of injurious falls (rate of falls resulting in one or more injuries for the duration of the study) could not be pooled in meta-analysis, hence results have been presented in a narrative form including tables. Standard GRADE (Grading of Recommendations Assessment, Development and Evaluation) evidence assessment of outcomes is also reported. Results: Nine studies were eligible for inclusion in this review. Eight articles were observational cohort studies which reported on the incidence/prevalence of falls as outcome measures, and one article was a quasi-experimental study design. Overall the methodological quality of the included studies was considered moderate. The pooled proportion of people with ID who fell (four studies, 854 participants) was 39% (95% CI [0.35%-0.43%], very low GRADE evidence). The rate of falls (eight studies, 782 participants) ranged from 0.54 to 6.29 per person year (very low GRADE evidence). The rate of injurious falls (two studies, 352 participants) ranged from 0.33 to 0.68 per person year (very low GRADE evidence). Conclusions: Synthesized findings demonstrate that people with ID, who live in community or residential settings, may fall more frequently, and at a younger age, compared to general community populations. Studies should take a consistent approach to measuring and reporting falls outcomes. Further research is recommended to identify the impact of falls on health related outcomes for people with ID and subsequently evaluate falls interventions for their efficacy.