Studies conducted in an institutional setting
Pooling of data from the 14 studies (11,808 participants) (see Table 2 for summary data from studies) conducted in nursing or residential care settings (Analysis 1.1) shows a small reduction in hip fractures with the provision of hip protectors (risk ratio (RR) 0.82, 95% confidence interval (CI) 0.67 to 1.00); the confidence interval, however, includes both no effect and an appreciable benefit of hip protectors. Using a typical baseline risk from studies (see Table 3), the calculated absolute effect is 11 fewer people per 1000 (95% CI from 20 fewer to 0) will have a hip fracture when provided with hip protectors in institutional settings. In a sensitivity analysis, the effect is reduced (RR 0.90, 95% CI 0.72 to 1.13; analysis not shown), following exclusion from the analysis of four studies (3092 participants) assessed as being at high risk of bias in the key domain of allocation concealment (Chan 2000; Hubacher 2001; Kannus 2000; Koike 2009). The analysis across studies with individual randomisation and studies with cluster randomisation (adjusted) shows similar results.
Table 2. Institutional studies: summary data for Analysis 1.1
| Study ID|| Randomisation method|| Protector design|
| Design effect applied to clustered studies|
| Cameron 2001||Individual||Hard (Safehip)||8||86||7||88||NA|
| Chan 2000||Individual||Soft||3||40||6||31||NA|
| Ekman 1997||Cluster||Soft, inserted under normal underwear||4||302||17||442||4.7|
| Harada 2001||Cluster||Hard (Safehip)||1||88||8||76||1.3|
| Hubacher 2001||Individual||Hard (Safehip)||7||384||2||164||NA|
| Jantti 1996||Individual||Soft||1||36||5||36||NA|
| Kannus 2000||Cluster||Shunting/ absorbing (KPH)||13||653||67||1148||1.5|
| Kiel 2007||All Individual participants had one protected and one unprotected hip. Protected side randomised by cluster||Shunting/ absorbing||17||1042||21||1042||NA|
| Koike 2009||Cluster||Hard (Safehip)||19||345||39||327||1.3|
| Lauritzen 1993||Cluster||Hard (Safehip)||8||247||31||418||1.6|
| Meyer 2003||Cluster||Hard (Safehip)||21||459||42||483||1.4|
| O'Halloran 2004||Cluster||Hard (Safehip)||85||1366||163||2751||1.7*|
| Van Schoor 2003||Individual||Hard (Safehip)||18||276||20||285||NA|
| Cameron 2011||Cluster||Hard (Hornsby Health Hips) and soft (Hip Saver)||4||139||1||96||2|
Table 3. Incidence of hip fractures per person year (control group participants) in descending order of incidence
|Study ID||Incidence (95% CI)|| Setting|| Country||Protection reported as effective||Randomisation|
| Chan 2000|| 0.261 (0.123 to 0.468)||Institutional||Australia||Yes||Individual|
| Jantti 1996|| 0.194 (0.095 to 0.353)||Institutional||Finland||Yes||Individual|
| Harada 2001|| 0.096 (0.047 to 0.181)||Institutional||Japan||Yes||Cluster|
| Koike 2009|| 0.079 (0.058 to 0.106)||Institutional||Japan||Yes||Cluster|
| Meyer 2003|| 0.076 (0.057 to 0.102)||Institutional||Germany||Yes||Cluster|
| Lauritzen 1993|| 0.068 (0.048 to 0.095)||Institutional||Denmark||Yes||Cluster|
| O'Halloran 2004|| 0.059 (0.050 to 0.102)||Institutional||United Kingdom||No||Cluster|
| Cameron 2001|| 0.053 (0.024 to 0.107)||Institutional||Australia||No||Individual|
| Van Schoor 2003|| 0.050 (0.032 to 0.077)||Institutional||Netherlands||No||Individual|
| Ekman 1997|| 0.042 (0.026 to 0.067)||Institutional||Sweden||Yes||Cluster|
| Kiel 2007|| 0.025 (0.016 to 0.040)||Institutional||USA||No||Individual|
| Cameron 2011|| 0.021 (0.006 to 0.073)||Institutional||Australia||No||Cluster|
| Hubacher 2001|| 0.017 (0.001 to 0.065)||Institutional||Switzerland||No||Individual|
| Kannus 2000|| 0.046 (0.036 to 0.058)||Institutional and supported living in community||Finland||Yes||Cluster|
| Cameron 2003|| 0.037 (0.025 to 0.056)||Living in community||Australia||No||Individual|
| Birks 2004|| 0.013 (0.010 to 0.016)||Living in community||United Kingdom||No||Individual|
| Birks 2003|| 0.012 (0.000 to 0.029)||Living in community||United Kingdom||No||Individual|
| Cameron 2011a|| 0.0 (-0.018 to 0.018)||Living in community||Australia||No||Cluster|
| Cameron 2011b|| 0.000 (-0.034 to 0.034)||Living in community||Australia||No||Individual|
Heterogeneity across all of the included studies in Analysis 1.1 is likely to be not important (I2 = 33%).
Overall, there is moderate quality evidence (due to risk of bias) for a small reduction in hip fractures with hip protectors in institutional settings (see Summary of findings for the main comparison).
Studies conducted in a community-dwelling setting
Four individually randomised studies recruited 5306 community-dwelling older people (Birks 2003; Birks 2004; Cameron 2003; Cameron 2011b) and one cluster randomised study recruited 308 community-dwelling older people who were admitted to hospital for hip fracture and later discharged into the community (Cameron 2011a) (see Table 4 for data used in analysis). The pooled analysis showed a small increase in or no effect on hip fractures with hip protectors (RR 1.15, 95% CI 0.84 to 1.58) (see Analysis 1.2). However, using a typical baseline risk from the included studies (see Table 3), the calculated absolute effect was two per 1000 more people (95% CI from 2 fewer to 6 more) with a hip fracture when provided with hip protectors in the community. The results of these studies showed no heterogeneity.
Table 4. Community studies: summary data for hip fractures (Analysis 1.2)
| Study ID|| Randomisation method|| Protector design|
| Design effect applied to clustered studies|
| Cameron 2003||Individual||Hard (Safehip)||21||302||22||298||NA|
| Birks 2004||Individual||Hard (Robinson Healthcare Ltd)||39||1388||66||2781||NA|
| Cameron 2011b||Individual||Hard (Hornsby Healthy Hips) or soft (Hip Saver)||1||118||0||53||NA|
| Cameron 2011a||Cluster||Hard (Hornsby Healthy Hips) or soft (Hip Saver)||4||205||0||103||3|
| Birks 2003||Individual||Hard (Safehip)||6||182||2||184||NA|
There was moderate quality evidence (due to risk of bias) that hip protectors probably had little or no effect on hip fractures in the community.
Pubic ramus and other pelvic fractures
Data on the incidence of pubic ramus and other pelvic fracture were available in nine studies (see Analysis 1.3). The risk ratio is 1.27 (95% CI 0.78 to 2.08). This result is imprecise due to the small number of events in the analysis (see Table 5 for absolute events per study) and the confidence interval include no effect as well as an appreciable harm. However, in absolute effects it would mean one more person per 1000 provided with a hip protector (95% CI from 1 fewer to 5 more) will have a pelvic fracture. Overall heterogeneity across community and institutional settings is I2 = 20% (no heterogeneity in community and I2 = 34% in institutions), but due to the small number of events, heterogeneity may have been difficult to detect across studies (in particular between O'Halloran 2004 and the other studies). There are similar effects on pelvic fractures between community and institutional settings, although the point estimate is greater in institutional settings. Overall, the evidence is low quality.
Table 5. Pelvic fractures: summary data for analysis 1.3
| Study ID|| Randomisation method|| Protector design|
| Design effect applied to clustered studies|
| Birks 2003||Individual||Hard (Safehip)||3||182||0||184||NA|
| Cameron 2003||Individual||Hard (Safehip)||8||302||6||298||NA|
| Birks 2004||Individual||Hard (Robinson Healthcare Ltd)||5||1388||15||2781||NA|
| Jantti 1996||Individual||Soft||0||36||2||36||NA|
| Kannus 2000||Cluster||Shunting/absorbing (KPH)||2||653||12||1148||1.5|
| Hubacher 2001||Individual||Hard (Safehip)||1||384||0||164||NA|
| Cameron 2001||Individual||Hard (Safehip)||2||86||2||88||NA|
| Van Schoor 2003||Individual||Hard (Safehip)||2||276||3||285||NA|
| O'Halloran 2004||Cluster||Hard (Safehip)||12||1366||6||2751||1.7*|
Data on the incidence of other fractures that occurred over the study periods were reported in 11 studies, but were disaggregated from pelvic fractures in six. Pooling of results from the six studies providing disaggregated data on fractures other than in the hip or pelvis shows little or no effect in rate of fractures (RateR 0.87, 95% CI 0.71 to 1.07) (see Analysis 1.4). The absolute effect is 26 fewer fractures per 1000 people provided with hip protectors over one year (95% CI from 58 fewer to 14 more). Pooling of data aggregating pelvic and other fractures together shows little or no effect in rate of fractures (RateR 0.88, 95% CI 0.75 to 1.05) (see Analysis 1.5). There is no heterogeneity across studies. The quality of evidence is moderate due to risk of bias.
Sixteen studies reported falls incidence; the pooled analysis shows little or no effect on the frequency of falls (RateR 0.99, 95% CI 0.87 to 1.13, Analysis 1.6). In people at low risk of falls, the absolute effect is 10 more falls per 1000 people (95% CI, from 50 fewer to 80 more); in people at high risk it is 60 more falls per 1000 people (95% CI, from 300 fewer to 480 more). There is however, considerable heterogeneity amongst these studies (Chi² = 198.69, df = 15 (P < 0.00001), I² = 92%), but it did not result in imprecise results. The overall quality of evidence is moderate.
O'Halloran 2004 reported on the occurrence of injurious falls (falls requiring medical attention): adjusted RateR 1.16 (95% CI 0.77 to 1.76) in a trial authors' analysis. Kannus 2000 reported on falls only in the protector group (1404 falls occurring in the 653 individuals).
Acceptance and adherence (also termed compliance)
Amongst those who were assigned to hip protectors, there was limited compliance with wearing them. Despite special efforts by some research groups (Kiel 2007; Meyer 2003; O'Halloran 2004; Van Schoor 2003) to improve acceptance and adherence through staff and participant education, acceptance and adherence remain low. In view of the different ways in which estimates of acceptance and adherence were presented, we did not attempt any summary estimate of frequency of use.
Birks 2003 gave an overall compliance figure of 34%. In Birks 2004, 17,222 individuals were identified who met the inclusion criteria (aged 70 years or over and having at least one risk factor for hip fracture) but 13,645 (79%) declined to participate. Of those who agreed, only 31% were still wearing the protectors daily by the end of the 28-month study. Cameron 2001 stated that the total compliance was 57%. At the end of this study only 37% were still regular wearers of the protectors. Cameron 2003 approached 1807 potential participants living in their own homes and 34% of these agreed to participate. By two years, the end of this study, only 33% to 38% of participants were wearing the protectors all the time. Cameron 2011a was also conducted in the community; adherence in hospitalised participants who were later discharged was 34% to 37%, and 48% to 51% for participants in the community at six months. Participants wore soft or hard protectors. Cameron 2011 included participants in nursing care facilities who wore hard shell protectors and found at six months that adherence was 34% to 36%. Chan 2000 reported a compliance of 50%, with dementia given as a reason for non-compliance. Ekman 1997 reported an average compliance of 44%, although it is not clear how this was calculated. Harada 2001 reported that 17/88 (19%) of those allocated to the protectors refused to wear them. Complete compliance, estimated by hours worn, was 70% and partial compliance was 17%. Hubacher 2001 reported that for 384 participants allocated to the protector group, 138 were regular wearers, 124 discontinued wearing them and 122 refused to wear them. Even the 138 'regular wearers' only wore the protectors 49.1% of the time. Jantti 1996 stated that of the 19 participants available at one year, 13 (68%) were still using hip protectors. In Kannus 2000, 31% of those who were eligible declined to participate in the study, and a further 71 out of 446 patients discontinued use during the study. Compliance in those who agreed to participate in the study (assessed as the number of days the protector was worn as a percentage of all available follow-up days) was 48% (± 29%, range < 1% to 100%). In Kiel 2007, participating residents were visited by research staff three times per week to assess adherence; this was throughout the trial, including the two-week run-in period. Reported adherence was initially about 60%, rose to 80% by the sixth month of the study and then fell again to less than 70% by the end of the study. Koike 2009 reported that compliance with hip protector use (for at least part of the day) was 79.7% throughout the study period. Of the subgroup of 45 individuals allocated to hip protectors monitored in Lauritzen 1993, only 11 (24%) wore the protectors regularly. Meyer 2003 recorded the compliance rate during fall events and reported that 68% in the intervention group versus 15% in the control group were wearing hip protectors at the time of a fall (see Feedback 3). O'Halloran 2004 reported that 37% of those allocated to wear the protectors at the start of the study agreed to do so. By 24 weeks of the study, 24% of those allocated to receive hip protectors were wearing them when visited by the research staff; this fell to 20% by 72 weeks. Van Schoor 2003 used random visits to assess compliance. At one month, 61% were compliant with wearing the protectors. This figure had fallen to 45% at six months and 37% at one year.
Chan 2000, Ekman 1997, Harada 2001 and Lauritzen 1993 all stated that no hip fractures occurred in those who fell while wearing the protectors. Five studies each reported that one hip fracture occurred while protectors were being worn (Birks 2004; Cameron 2001; Cameron 2011; Cameron 2011b; Jantti 1996). In Cameron 2001 the protector was not properly applied, in Birks 2004 the person fell backwards, and in Jantti 1996 the fracture was attributed to the pants being too large and the pads slipping out of place. Kannus 2000 and Van Schoor 2003 each reported that four hip fractures occurred whilst protectors were being worn. Cameron 2003 also reported four hip fractures whilst wearing the protectors: two were backward falls, one a spontaneous fracture and one occurred from a road traffic accident. In Meyer 2003, four participants in the intervention group sustained hip fractures that may have occurred while hip protectors were being worn. Kiel 2007 reported that 13 hip fractures occurred in protected hips while residents were wearing hip protectors. In Koike 2009, seven out of the 19 fractures in the intervention group occurred in falls while hip protectors were worn. O'Halloran 2004 stated that 13% of fractures in residents of intervention homes occurred while protectors were being worn.
Complications (including skin damage or breakdown)
Not all studies measured complications, and studies often combined reporting of these with reasons for non-compliance. In studies that did report on complications, there was a range of event rates that were small (˜ 0% to 5%). In Birks 2004, one hip fracture resulted from falling while putting on a protector. Minor skin irritation was reported in Cameron 2001, and Cameron 2003 reported minor skin irritation or infection caused by hip protectors in 16 users (5%). Cameron 2011, Cameron 2011a and Cameron 2011b asked participants open-ended questions about complications, but no complications were reported. Chan 2000 indicated that one staff member noted that the underwear had rubbed. Ekman 1997 mentioned that the occurrence of skin irritation was used as a reason for non-compliance. Hubacher 2001 reported that aches and pains and an uncomfortable feeling while wearing the protectors were given as a reason for non-compliance. Kannus 2000 reported skin irritation or abrasion in 15 cases. In addition, one person reported that the protector caused swelling of the legs and another that it caused bowel irritation. In Kiel 2007, no skin-related or mobility-related adverse effects occurred. Koike 2009 reported that "six residents in the intervention group reported skin-related adverse events and refused to wear hip protectors from that time on". Meyer 2003 reported five cases of skin irritation. In addition, some of the care homes reported increased dependency of some of the residents at toileting, more difficulty in dressing and discomfort from wearing the protectors.
We found 12 economic evaluations of the use of hip protectors. Economic outcomes were available from two of the included studies (Meyer 2003; Van Schoor 2003). Ten other economic evaluations modelled the possible impact of provision of hip protectors in different health delivery systems in North America and Europe.
Seven economic evaluations conducted in North America assumed efficacy of hip protectors, derived from one or more of the early cluster randomised studies or from pooled data in the 2001 version of this Cochrane review (Parker 2001), and conducted economic modelling relevant to their health system.
Four evaluations were conducted in the USA (Colon-Emeric 2003; Honkanen 2005; Honkanen 2006; Segui-Gomez 2002).
Colon-Emeric 2003 conducted a cost-effectiveness and cost-utility analysis using a societal perspective and an 18-month time horizon. They concluded that “using external hip protectors in nursing facilities is cost saving or economically attractive over a wide range of cost and utility assumptions”.
Honkanen 2005 used a Markov model considering the short-term and long-term outcomes of hip protectors for a hypothetical nursing home population, stratified by age, sex and functional status. Estimates of hip protector effectiveness were derived from Kannus 2000, and costs and transition probabilities between health states were from other published secondary data. From a Medicare perspective, hip protectors appeared to be potentially cost-saving in the nursing home environment across almost all sex and functional groups aged 65 years and older, and for the nursing home population as a whole when adherence was greater than 42% and residents used three hip protectors a year.
Honkanen 2006 used a Markov model similar to that in Honkanen 2005, conducting a cost-utility analysis of using hip protectors in a community-dwelling population compared with no intervention. In this setting, the analysis demonstrated that hip protector use was the dominant strategy only in women who initiated use at the age of 80 or 85 years, and in men who initiated use at the age of 85 years.
Segui-Gomez 2002 modelled two hypothetical cohorts of 500,000 65-year-old men or women with and without hip protectors through to death or the age of 100 years, whichever was earlier, using the data from Kannus 2000 to give an efficacy estimate of 56% (sensitivity analysis range 43 to 69). In this model, everyone in the hip protector cohort was assumed to show 100% adherence for the base case but sensitivity analyses explored the effect of lower levels. At an efficacy estimate of 13% (compatible with the evidence from our Analysis 1.1 and Analysis 1.2), net costs were generated. Hip protectors for women would be cost saving with adherence above 23%.
Three economic evaluations were reported from Canada (Sawka 2007b; Singh 2004; Waldegger 2003).
Sawka 2007b used a pooled odds ratio of 0.40 (95% CI 0.25 to 0.61) from a meta-analysis (Sawka 2007a, which included Ekman 1997; Harada 2001; Jantti 1996; Meyer 2003) in a model-based economic analysis, using estimates of transition probabilities, costs and utilities relevant to Canada. Assumed compliance was as in these four studies. They concluded that if hip protectors could be provided to elderly Ontario nursing home residents without additional labour expenditures, there was a reasonable probability that such a strategy might result in healthcare cost savings.
Singh 2004 modelled the cost-effectiveness of hip protectors in the prevention of hip fractures using data from literature current at that time, and from the care of elderly nursing home residents in a community hospital in British Columbia, Canada. They found that hip protector use was a dominant strategy compared to no treatment and to calcium and vitamin D supplements, and could save money while preventing hip fractures and improving quality of life.
Waldegger 2003 conducted a meta-analysis of five early cluster randomised studies that were at high risk of bias (Chan 2000; Ekman 1997; Harada 2001; Kannus 2000; Lauritzen 1993) assuming a relative risk of hip fracture of 0.40 (95% CI 0.23 to 0.70) and an adherence range of 25% to 50%. Using these assumptions, their economic analysis indicated that hip protectors were a cost-effective method of preventing hip fracture in an institutionalised elderly population.
Five economic evaluations were conducted in northern Europe, three of which were modelling studies (Fleurence 2004; Gandjour 2008; Kumar 2000), and two had been conducted as a prospectively planned and conducted component of studies included in this review (Meyer 2003; Van Schoor 2003).
Fleurence 2004 (UK) developed a Markov model to follow a hypothetical cohort of males and females at high risk and general risk of fracture. They concluded that “Current information available on interventions to prevent fractures in the elderly in the United Kingdom, suggests that, at the decision-maker’s ceiling ratio of $20,000 per quality adjusted life year (QALY), hip protectors were cost-effective in the general female population and high-risk male population, and cost-saving in the high-risk female population, despite the low compliance rate with the treatment".
Gandjour 2008 (Germany) reported the use of a Markov simulation of two cohorts of 100,000 hypothetical patients, one offered hip protectors and the other not. In their analysis, they use the pooled estimate of effectiveness from the previous update of this Cochrane review (RR 0.77, 95% CI 0.62 to 0.97). Adherence of 50% was assumed; so was use of protectors up to a total of two years by other individuals if the first wearer were to stop earlier. The base-case analysis found that wearing hip protectors would lead to savings of EUR 315 and a gain of 0.13 QALYs per patient. The probability of savings was 99%; only with an assumption of low hip protector effectiveness or high mortality rate at six months after fracture would these savings not be realised; however, some uncertainty about cost-effectiveness did remain.
Kumar 2000 (UK) modelled the additional costs of providing three pairs of hip protectors to older people in the catchment area of a district general hospital using: contemporary costs for 1998; an assumption of effectiveness based on the three studies in this review that were published before 2000 (Ekman 1997; Jantti 1996; Lauritzen 1993); and detailed age and gender data based on a four-year observational study. The results suggested that for people aged over 84 years, wearing hip protectors appeared to be cost-effective, but that further evaluation of effectiveness, costs and compliance was desirable.
In Meyer 2003, (Germany), in which a planned economic evaluation was conducted alongside the clinical study, education about and provision of hip protectors did reduce hip fracture incidence but was found to produce a slight increase in costs, although cost savings might be made if the price of the hip protectors could be decreased.
Van Schoor 2003 (Netherlands) conducted an economic evaluation alongside the clinical study, which found that provision of hip protectors was neither effective nor associated with lower costs.