Environmental and behavioural interventions for reducing physical activity limitation and preventing falls in older people with visual impairment

Authors: E JY, Li T, McInally L, Thomson K, Shahani U, Gray L, Howe TE, Skelton DA.

Geographical coverage: Australia, Hungary, New Zealand, the UK, the US

Sector: Prevention

Sub-sector: Environmental and behavioural interventions

Equity focus: Elderly

Study population: Elderly with visual impairments

Review type: Other review

Quantitative synthesis method: Narrative synthesis

Qualitative synthesis method: Not applicable

Background:

Impairment of vision is associated with a decrease in activities of daily living. Avoidance of physical activity in older adults with visual impairment can lead to functional decline and is an important risk factor for falls. The rate of falls and fractures is higher in older people with visual impairment than in age-matched visually normal older people. Possible interventions to reduce activity restriction and prevent falls include environmental and behavioural interventions.

Objectives:

Assess the effectiveness and safety of environmental and behavioral interventions in reducing physical activity limitation, preventing falls and improving quality of life amongst visually impaired older people.

Main findings:

Authors included six randomised controlled trials conducted in five countries (Australia, Hungary, New Zealand, the UK, the US) with follow-up periods ranging from two to 12 months. Participants in these trials included older adults (mean age 80 years) and were mostly female (69%), with visual impairments of varying severity and underlying causes. Participants mostly lived in their homes and were physically independent.

Authors classified all trials as having high risk of bias for masking of participants, and three trials as having high or unclear risk of bias for all other domains. The included trials evaluated various intervention strategies (for example, an exercise programme versus home safety modifications). Heterogeneity of study characteristics, including interventions and outcomes, (such as different fall measures), precluded any meta-analysis.

Authors found two trials comparing the home safety modification by occupational therapists versus social/home visits. One trial (28 participants) reported physical activity at six months and showed no evidence of a difference in mean estimates between groups (step counts: mean difference (MD) = 321, 95% confidence interval (CI) -1981 to 2623; average walking time (minutes): MD 1.70, 95% CI -24.03 to 27.43; telephone questionnaire for self-reported physical activity: MD -3.68 scores, 95% CI -20.6 to 13.24; low certainty of evidence for each outcome). Authors found two trials reporting the proportion of participants who fell at six months (risk ratio (RR) 0.76, 95% CI 0.38 to 1.51; 28 participants) and 12 months (RR 0.59, 95% CI 0.43 to 0.80, 196 participants) with low certainty of evidence for each outcome. One trial (28 participants) reported fear of falling at six months, using the Short Falls Efficacy Scale-International, and found no evidence of a difference in mean estimates between groups (MD 2.55 scores, 95% CI -0.51 to 5.61; low certainty of evidence). This trial also reported quality of life at six months using 12-Item Short Form Health Survey, and showed no evidence of a difference in mean estimates between groups (MD -3.14 scores, 95% CI -10.86 to 4.58; low certainty of evidence).

Authors included five trials comparing behavioural intervention (exercise) versus usual activity or social/home visits. Authors found no evidence of a difference between groups on self-reported physical activity at six months; found no evidence of a difference in effect estimates on falls measures at six or 12 months. Furthermore, in three trials which assessed the fear of falling from two to 12 months, the authors found no evidence of a difference in mean estimates between groups. In one trial which assessed European Quality of Life scale at six months, the authors found no evidence of a clinical difference between groups.

Authors conclude there is no evidence of effect for most of the environmental or behavioural interventions studies for reducing physical activity limitation and preventing falls in visually impaired older people. The certainty of evidence is generally low due to poor methodological quality and heterogeneous outcome measures.

Authors also note that researchers should form a consensus to adopt standard ways of measuring physical activity and falls reliably in older people with visual impairments. Fall prevention trials should plan to use objectively measured or self-reported physical activity as outcome measures of reduced activity limitation. Future research should evaluate the acceptability and applicability of interventions and use validated questionnaires to assess the adherence to rehabilitative strategies and performance during activities of daily living.

Methodology:

Eligible studies were randomised controlled trials (RCTs) and quasi-randomised controlled trials (Q-RCTs) that compared environmental interventions, behavioural interventions, or both, versus control (usual care or no intervention); or that compared different types of environmental or behavioural interventions. Eligible study populations were older people (aged 60 and over) with irreversible visual impairment, living in their own homes or in residential settings. To be eligible for inclusion, studies must have included a measure of physical activity or falls, the two primary outcomes of interest. Secondary outcomes included fear of falling, and quality of life.

Authors searched CENTRAL (including the Cochrane Eyes and Vision Trials Register) (Issue 2, 2020), Ovid Medline, EMBASE and eight other databases to 4 February 2020, with no language restrictions. Review authors also contacted authors of ongoing trials or abstracts found and searched the reference lists of full papers reviewed. There were no restrictions to language or year of publication.

Authors used Cochrane standard methods where two reviewers independently screened studies for inclusion, extracted data and assessed the certainty of the evidence using the GRADE approach.

Applicability/external validity:

The study’s participant characteristics varied due to different enrolment methods and inclusion criteria. Some trials recruited younger individuals or those with less severe vision loss, while others targeted older community-dwelling individuals with vision impairment. Recruitment was sometimes through low vision clinics or targeted those with specific eye diseases like age-related macular degeneration. However, the exclusion of participants with neurological disorders or mobility issues in their residence may limit the applicability of the results to older individuals with cognitive impairment or those living in dependency.

Geographic focus:

Authors note that included trials were conducted in five countries with different health care systems; therefore, the effectiveness of interventions could be sensitive to a variety of health care structures and networks settings. The results of this review should be interpreted with caution because four trials had low power to detect effect due to small sample size.

Furthermore, authors note that given the complexity of environmental and behavioural interventions and relatively small size of the six trials in this review, it is not possible to establish the applicability of the heterogeneous evidence in different settings and we do not know whether any benefits exist.

Summary of quality assessment:

Review authors used appropriate and rigorous methods to identify and screen studies for inclusion, and extract and appraise included studies. Authors appropriately synthesised evidence narratively from included trials, given the substantial clinical or statistical heterogeneity. However, authors provided the effect of estimates and, when appropriate, pooled results for comparable groups of studies. In light if this, we have high confidence in the findings of this review.