The risk factors for reduced physical function in elderly people, as identified in longitudinal studies,^5,6 relate to comorbidities, physical and psychosocial health, environmental conditions, social circumstances, nutrition, and lifestyle. The need for a preventive strategy based around identification and treatment of diverse risk factors was identified more than 40 years ago,⁷ and many trials of complex intervention packages have been reported and reviewed. In this context, a complex intervention can be regarded as a combination of interdisciplinary teamwork for health and social problems. Trials have focused on general and frail elderly populations,^8–11 elderly people discharged from hospital,¹² and those at risk of falling.^13–15 However, the development of risk factors, admission to hospital, and risk of falling represent a common chain of experiences for many elderly people.¹⁶ Likewise, multifactorial interventions in these populations have common characteristics and, in addition to targeting specific outcomes relating to hospital readmissions and falls, share the common aims of physical function maintenance, disability limitation, and promotion of independence.

In the UK, yearly multidimensional assessments of physical and cognitive health for all individuals aged at least 75 years became a necessity in primary care in 1989,¹⁷ with guidelines on content and implementation provided for England.¹⁸ In due course, a targeted approach to assessment and care was developed and promoted with community nurse-led case management of elderly people with medical conditions identified from hospital admissions and general practice records.¹⁹ The report²⁰ stresses the importance of a team-based approach incorporating appropriate skills to meet the health and care needs of elderly people.

Geriatric screening and multidimensional assessment are recognised in modernised health-care systems in Germany, Italy, France, the Netherlands, and Denmark.²¹ In US-managed care organisations, the focus of care is on frail elderly people and those discharged from hospital.²² Care is coordinated by case managers and this model has been applied in other countries, including England.²³

Randomisation was by individual or household (n=80) or by clusters of general practices, community groups, or municipalities (n=9). The total number of people randomised was 97 984 with a median of 321 (range 54–43 219) in trials. One large study randomised 43 219 people.³³ Mortality rates ranged from 0 to 60·8% per year, with a median of 6·8%. Trials assessing geriatric assessment in general and frail populations had median mortality rates of 5·4% (0–10·5%) and 6·1% (1·1–60·8%), respectively, suggesting that the frail category was often subject to selection, probably indicating eligibility issues. In trials of community-based care after hospital discharge, the median mortality rate was 16·2% (6·3–53·0%); for fall prevention and group education, it was 4·3% (0–11·6%) and 3·4% (2·7–4·4%), respectively.

Losses to follow-up were used as a marker of study quality. In trials with death as an outcome, 40 (48%) of 84 had losses to follow-up of 1% or less (range 0–27·6%). For physical function, few trials included people who had died or moved to nursing homes in their analyses; exceptions were Close¹⁰⁰ and Gagnon⁶¹ and their colleagues' trials. 15 (35%) of 43 trials had losses of participants to follow-up for interview of 5% or less (0–33%).

The allocation process was described in 61 (69%) of 89 trials, but difficulties of assessing concealment and masking in complex intervention trials are unlikely to have been fully addressed.¹¹⁴ Intervention activity in control groups was evident in 40 (45%) of 89 trials.

Data for variability between clusters were insufficient and the effect of analysis errors arising from inclusion of cluster randomised trials was explored by sensitivity analysis. Inspection of funnel plots at all stages of the review gave no indication of selection bias in studies included in the analysis (data not shown).

Outcomes are summarised by type of intervention in the table. The outcome of living at home at follow-up was available for 51 interventions; in a further nine trials death and nursing-home admission were used, with the consequent inclusion of the large Medical Research Council (MRC) trial.³³ Overall, 60 (67%) of 89 trials reported living at home at follow-up or an estimate. However, this outcome was reported in only 4 [31%] of 13 trials.

In a meta-analysis of 60 trials with 79 578 individuals (figure 2), the overall risk of not living at home was lower in the intervention group (RR 0·95, 95% CI 0·93–0·97) than in the control group. Geriatric assessment of general elderly people and community-based care after hospital discharge were the only types of intervention that had a significant effect on the risk of not living at home (figure 2). Removal of trials with estimated values had little effect (0·95, 0·90–1·00). Heterogeneity was only manifest in trials of geriatric assessment in general populations and those selected as frail (figure 2).

If typical rates of not living at home of about 7·6% (median in trials; range 0–12·1) per year for the general population are used, and the reduction in risk from intervention is 5%, a number needed to treat of 263 is obtained. For the increased rates of not living at home in people receiving community-based care after hospital discharge of about 25% per year with an RR reduction of 9%, the number needed to treat is 40.

Data for death were available for 84 (94%) of 89 interventions including 93 754 people (webfigure 1). Interventions had no overall benefit (RR 1·00, 95% CI 0·97–1·02) and the only appreciable benefit by type of intervention was noted in 11 trials targeting fall prevention (0·79, 0·66–0·96; webfigure 1). Slight heterogeneity (I²=10·6%) was almost exclusively limited to trials of geriatric assessment in general elderly populations (I²=39·7%; webfigure 1).

Data for nursing-home admission (31 trials) or for residence at follow-up (23 trials) were available for 79 575 people (webfigure 2) and were widely reported in trials of geriatric assessment in general (20 [71%] of 28) or populations selected as frail (16 [67%] of 24) and community-based care after hospital discharge (14 [67%] of 21), but not in trials of fall prevention (3 [23%] of 13).

For combined nursing-home outcomes, risk of admission was reduced in the intervention group (RR 0·87, 95% CI 0·83–0·90; webfigure 2). Only a marginal effect was seen for residence at follow-up (0·93, 0·79–1·09). Geriatric assessment and community-based care after hospital discharge were the only types of intervention to have a significant effect on the combined outcome (webfigure 2). Some heterogeneity was recorded in trials (I²=29·0%), mainly in geriatric assessment in general populations (I²=47·5%; webfigure 2).

For nursing-home care, typical median rates for trial populations were 2·2% (range 0·1–5·4) per year for the general population and 11·1% (2·1–40·2) per year for people receiving community-based care after hospital discharge, generating numbers needed to treat of 354 and 39, respectively.

Hospital admissions were reported in between 5 (38%) of 13 (falls prevention) and 18 (86%) of 21 (community-based care after hospital discharge) trials. The most commonly reported outcome—number of people having an admission (41 trials with 20 047 people [webfigure 3])—was used in the meta-analysis. Risk of hospital admission was reduced by interventions (RR 0·94, 95% CI 0·91–0·97; webfigure 3). Geriatric assessment in elderly people selected as frail and community-based care after hospital discharge were the only types of interventions to show significant effect on this outcome. Heterogeneity (I²=43·0%) was largely restricted to geriatric assessment in general elderly patients and community-based care after hospital discharge (61·4% and 57·0%, respectively; webfigure 3). In random-effects meta-analysis, the overall RR was similar (0·94, 95% CI 0·89–0·99).

Trials with data that were incompatible with the meta-analysis were inconsistent, with hospital admissions reduced in seven,^{33,40,42,56,94,100,113} similar in four,^68,70,80,87 and increased in five trials.^{46,53,54,58,61} The large MRC trial reported slightly reduced total admissions in the intervention group (RR 0·96, 99% CI 0·79–1·16).³³

All 13 studies targeting fall prevention reported individuals who had fallen, whereas falls were less likely to be reported in trials in general elderly people (6 [21%] of 28 trials), frail elderly people (5 [21%] of 24), and those with community-based care after hospital discharge (5 [24%] of 21). No trials of group education reported falls. An overall benefit was noted in 25 trials including 15 607 people (RR 0·90, 95% CI 0·86–0·95; webfigure 4). Interventions targeting fall prevention contributed 66% of the weight. Only trials of geriatric assessment in general elderly populations and those of fall prevention showed significantly reduced falls (webfigure 4). Heterogeneity (I²=52·8%; webfigure 4) was restricted to trials of community-based care after hospital discharge (I²=40·3%) and fall prevention(I²=65·8%). Use of random-effects meta-analysis led to wide CIs including unity for the interventions targeting fall prevention (0·91, 0·82–1·00), but the overall effect including all trials was broadly similar (0·89, 0·83–0·96). The four trials that did not report individuals who had fallen showed benefit with reduced total falls in intervention groups.^29,66,91,102

Physical function outcome was measured in 73 trials. The Barthel index of activities of daily living restrictions (n=14) and SF-36 physical function dimension (n=7) were frequently reported. Information on change and functional deterioration was available for only nine and 16 studies, respectively, and we used the widely available physical function at follow-up in our analyses.

Meta-analysis included 43 interventions with 21 651 individuals (webfigure 5). Sources of variance data are available from the authors. In Reuben and colleagues' trial,⁶⁸ substantial differences at baseline between randomised groups were reported, and analyses were done both with and without these data. In 36 trials with activities of daily living outcome, an overall benefit for interventions was noted (SMD −0·08, 95% CI −0·11 to −0·04) and in 14 trials with a generic physical function outcome that did not specifically focus on disability, the effect was similar (−0·09, −0·13 to −0·05). Exclusion of the trial with baseline differences had little effect on the SMD, and heterogeneity was evident for both outcomes (I²=37·5% and I²=57·5%, respectively).

When SF-36 physical function means and variances from the 1992 Office for National Statistics survey were used,¹¹⁵ an SMD of 0·09 translated as an improvement in a representative elderly population of between 3·3% and 7·2% dependent on age. For the Barthel index, in the trials included in the review, the SMD of 0·08 equated to about half a point improvement in the 20-point score.

Combination of activities of daily living and generic outcomes (only used if no activities of daily living outcome reported) showed a similar benefit (SMD −0·08, 95% CI −0·11 to −0·06; webfigure 5). Heterogeneity was little different in the combined analysis to that seen when activities of daily living and generic measures were analysed separately and was mainly restricted to trials of geriatric assessment in elderly people selected as frail. However, RRs were much the same in random-effects meta-analysis (−0·08, −0·13 to −0·04). Geriatric assessment in general populations and falls interventions showed benefit for physical function at follow-up when grouped by context.

Physical function was reported in a form unsuitable for meta-analysis in 30 trials. Two interventions showed improvement in activities of daily living^76,97 and five showed weak evidence of benefit.^33,50,73,81 However, no improvement was noted in 19 trials,^{30,31,38,42,44,47,48,59,71,77,83,86,93,95,98,102,108,111,113} and in four trials generic physical function was largely unaffected by interventions.^51,59,86

Study quality in terms of losses to follow-up (webtable 2) and randomisation process did not affect our findings—eg, RR of not living at home in 19 trials in which the randomisation process was not clear was 0·92 (95% CI 0·85–0·98), similar to that reported in trials with a clear description of randomisation (0·95, 0·93–0·98).

Analysis of results excluding trials with cluster randomisation had little effect on the overall RRs and variances. The contribution of the cluster randomised MRC trial to the meta-analyses was large, providing 71%, 58%, and 73% of not living at home, death, and nursing-home admission events, respectively. However, after exclusion of the trial, the results were reasonably consistent with RRs of 0·94 (95% CI 0·90–0·98) and 0·90 (0·83–0·97) for not living at home and nursing home admissions, respectively. When the MRC trial was excluded, the RR of death was reduced, although the 95% CI included unity (0·96, 0·92–1·00).

In trials with increased death rates, the RR of not living at home was reduced (second quartile of death rate 0·91, 95% CI 0·84–0·98, p=0·02; third quartile 0·96, 0·93–0·98, p=0·01; and fourth quartile 0·88, 0·79–0·96, p=0·05; webtable 3). Similarly, nursing-home admissions were reduced after intervention in populations with high death rates, which differed significantly from one for the two highest quartiles (third quartile of death rate 0·86, 0·82–0·90, p<0·0001, and fourth quartile 0·75, 0·63–0·89, p=0·01; webtable 3).

In trials with recruitment dates before the median of 1993, interventions showed benefit with a combined RR of not living at home of 0·89 (95% CI 0·84–0·93; webtable 4), whereas in trials from 1993 onwards the RR was 0·97 (0·94–0·99). Removal of the MRC trial from the analysis made this difference even more pronounced (1·04, 0·96–1·12) in trials from 1993 onwards. In meta-regression, the outcomes of not living at home, death, and nursing home admission all showed increased risk reduction in studies before 1993 (webtable 4). This increased risk reduction was also apparent for specific contexts—eg, for community-based care after hospital discharge, RR of not living at home in studies started before 1993 was 0·82 (0·73–0·93) compared with 1·01 (0·87–1·17) in later studies. Younger participants (≤74 years) tended to benefit more than elderly participants for all outcomes except hospital admission (webtable 5) and nursing-home admission.

However, meta-analysis including trials done since 1993 suggested that modification of care beyond that achieved after earlier developments has been of little additional value. The 1980s to 1990s was a dynamic period in the specialty of care of elderly people. In the UK, the 1990 General Medical Services contract and the commission of the MRC trial of assessment and management of elderly people in the community affected the care of elderly people. Overall, care probably improved during this period because some of the principles of effective care became incorporated in normal practice.

The need for assessment of interventions was highlighted by the perceived ineffectiveness of the UK Evercare pilot programmes in relation to hospital admissions and death.²³ This model involved nurse-led assessment and case management for people with long-term conditions. The UK assessment did not use a randomised approach and we identified no randomised controlled studies of the model in our widespread searches of published work. On the basis of our systematic review, we would not have expected reductions in hospital admissions or deaths in those people receiving assessment and case management.

In our review, the eligibility for care covered the broad experience of elderly people and in general the results were consistent with previous meta-analyses. Elkan and colleagues⁹ reported an overall benefit for home-visiting programmes in prevention of death and nursing-home admission. Stuck and coworkers¹¹ noted benefit for home-visiting programmes, which was restricted to improvements in physical function with multidimensional assessment and many follow-ups, reduction in nursing-home admissions with increased numbers of follow-up visits, and reductions in mortality with application in younger populations (72·7–77·5 years). These reviews assessed 15 and 18 interventions, respectively. Assessment and multifactorial intervention have also shown benefit with reduction in rate of falls in three to 13 trials.^13–15 Review of nine trials targeting people after hospital discharge showed some benefits with regard to living at home and institutionalisation.¹²

We used the principle that interventions relating to different aspects of care can be judged together as complex interventions. The interventions in this review had input from a wide range of health-care disciplines with different intensity and duration of care, but all addressed issues of preventive visits for elderly people with care based on assessment of medical and social need. Intensity, indicating direct multidisciplinary input, number of scheduled visits, and the duration of the intervention, might not capture the effective characteristics of the intervention. Inclusion of a qualitative element in trials would have helped to understand the care actually received by individuals.

Trials specifically targeting falls prevention included interventions that were more strongly focused on home safety and physical health than other trials included in this review. However, all interventions included in the review addressed diverse issues of medical and social care. Exclusion of trials specifically targeting fall prevention made little difference to overall outcomes, including risk of falling (RR 0·88, 95% CI 0·81–0·95).

The outcome of living at home might be an over simplistic marker for independent living. In Byles and colleagues' study,²⁸ increased admissions to nursing homes in the intervention group were attributed to the assessment process and advice given. The intervention might have led to improved understanding of the limitations of home-based care and increased awareness of alternative care available in nursing homes. Conversely, if limitation of health-care use and costs are the main objectives, unfavourable care patterns for both the individual and carers might arise.

Interpretation of results related to physical function is restricted by selective reporting in people readily available for interview follow-up and by the large losses to follow-up in trials. Previous reviews have reported the number of people with functional deterioration, but this outcome was only available for a small number of trials. A further limitation in reporting changes in physical function is the large number of different outcome measures reported.

Other outcomes, including empowerment, autonomy, independent decision making, improved self esteem, and self confidence might accurately describe the effect of an intervention to the individual.¹¹⁶ Close and colleagues¹⁰⁰ measured ability to go out alone as an outcome, perhaps a better marker of independence; and Kerse and colleagues³⁸ obtained information on how often people did something they really enjoyed and the frequency of interactions with family and friends. Rockwood and colleagues⁶⁹ used goal attainment scaling as part of the intervention and follow-up.¹¹⁷ This method aimed to assess specific outcomes based on personal goals set during intervention. Various other outcome measures related to health and psychosocial status and satisfaction with care and health-service use were reported, but their diversity and application in only a few trials restricted their value in a systematic overview.

A strength of our review is the inclusion of the large MRC trial of assessment and management of elderly people in the community. Recruitment to the trial commenced in 1995 and in the context of our review is a late trial. However, the authors note that annual assessments, as promoted in the UK, were poorly implemented at this time. Although the cluster design was associated with reduced study power and the study lacked an untreated control group, the MRC trial served to support the overall meta-analysis. Although not significant at the prespecified 1% level, the reported RR for institutional admissions was 0·83 (99% CI 0·66–1·06), which was reasonably similar to that in our meta-analysis (0·87, 0·82–0·91). The outcome of living at home was not available, but an estimate based on the sum of deaths and institutional admissions again suggested similar benefit in the large trial and the meta-analysis. Neither approach showed benefit with regard to death.

Because the evidence did not suggest that one format of care provision was better than another, the possibility might exist to tailor different formats of care to the needs and preferences of the individual, a conclusion similar to that drawn from the UK assessment of an expert patient programme.¹¹⁸ Provision of alternative intervention formats and intensities could lead to better uptake and adherence with care without compromising potential benefit.