A critical structured review of economic evaluations of interventions for the prevention and treatment of osteoporosis

Osteoporosis is a major cause of morbidity, mortality and resource cost amongst the elderly population. Hip fracture is the most serious of the osteoporotic fractures, with approximately 10-20% of patients dying within six months of sustaining a fracture. Furthermore, hip fractures are the most expensive manifestation of osteoporosis, incurring about 87% of the total costs of osteoporotic fractures. This public health and economic burden is likely to increase in developed nations due, in part, to ageing populations. In addition, there is strong evidence that the age-specific incidence of fracture is rising. There are a number of treatments which can be used to prevent fracture including hormone replacement therapy (HRT), bisphosphonates, vitamin D and calcium. These interventions have been used for primary prevention, secondary prevention and the treatment of established osteoporosis. This Discussion Paper details the results of a structured review, the purpose of which was to identify and critically appraise economic evaluations relating to interventions for osteoporosis. The focus of the work is a critical assessment of the methodology of those studies. A total of 16 economic evaluations was identified on the basis of a computerised search of three bibliographic databases. All studies were based on decision analytical models and all took the form of cost-effectiveness analysis. Seven studies were from the US and four from the UK. The majority of studies focused on either primary prevention alone (seven) or both primary and secondary prevention where high-risk women were identified on the basis of bone mineral density screening (seven). Most studies considered the cost-effectiveness of HRT. Most of the published studies conclude that treatment using HRT is relatively cost-effective among symptomatic women or women who have had a prior hysterectomy. In contrast, for asymptomatic women, the results are more equivocal. The most recent cost-effectiveness analysis was undertaken by the National Osteoporosis Foundation (NOF) which makes the explicit assumption that HRT is the treatment of choice. For women unwilling or unable to take HRT, the next recommended treatment was alendronate; should alendronate not be tolerated, calcitonin was recommended. Many of the models included in the review exhibit methodological weaknesses which suggest heir results should be treated with some caution. One of these concerns the dearth of formally elicited health state preference data from patients or members of the public: only two studies in the review derive preferences empirically rather than use the authors’ judgement. A second limitation of many studies is the inappropriate application of costeffectiveness decision rules with the frequent use of average cost-effectiveness ratios. Areas of methodological controversy, such as whether or not to include costs unrelated to osteoporosis in life-years added as a result of treatment, increase uncertainty regarding how to interpret the results of the studies.osteoporosis, HRT

Hormone replacement therapy and prevention of vertebral fractures: a meta-analysis of randomised trials

BACKGROUND: Hormone replacement therapy (HRT) is often seen as the treatment of choice for preventing fractures in women. We undertook a recent meta-analysis of randomised trials which suggested that HRT reduced non-vertebral fractures by 30%. In this analysis we extend that analysis to vertebral fractures. METHODS: We searched the main electronic databases until the end of August 2001. We sought all randomised controlled trials (RCTs) of HRT where women had been randomised to at least 12 months of HRT or to no HRT. RESULTS: We found 13 RCTs. Overall there was a 33% reduction in vertebral factures (95% confidence interval (CI) 45% to 98%). CONCLUSIONS: This review and meta-analysis showed a significant reduction in vertebral fractures associated with HRT use

Randomised controlled trial of exercise for low back pain : clinical outcomes, costs and preferences

Objective: To evaluate effectiveness of an exercise programme in a community setting for patients with low back pain to encourage a return to normal activities. Design: Randomised controlled trial of progressive exercise programme compared with usual primary care management. Patients' preferences for type of management were elicited independently of randomisation. Participants: 187 patients aged 18-60 years with mechanical low back pain of 4 weeks to 6 months' duration. Interventions: Exercise classes led by a physiotherapist that included strengthening exercises for all main muscle groups, stretching exercises, relaxation session, and brief education on back care. A cognitive-behavioural approach was used. Main outcome measures: Assessments of debilitating effects of back pain before and after intervention and at 6 months and 1 year later. Measures included Roland disability questionnaire, Aberdeen back pain scale, pain diaries, and use of healthcare services. Results: At 6 weeks after randomisation, the intervention group improved marginally more than the control group on the disability questionnaire and reported less distressing pain. At 6 months and 1 year, the intervention group showed significantly greater improvement in the disability questionnaire score (mean difference in changes 1.35, 95% confidence interval 0.13 to 2.57). At 1 year, the intervention group also showed significantly greater improvement in the Aberdeen back pain scale (4.44, 1.01 to 7.87) and reported only 378 days off work compared with 607 in the control group. The intervention group used fewer healthcare resources. Outcome was not influenced by patients' preferences. Conclusions: The exercise class was more clinically effective than traditional general practitioner management, regardless of patient preference, and was cost effective

Systematic review of topical treatments for fungal infections of the skin and nails of the feet

OBJECTIVE: To identify and synthesise the evidence for efficacy and cost effectiveness of topical treatments for superficial fungal infections of the skin and nails of the feet. DESIGN: Systematic review. INTERVENTIONS: Topical treatments for superficial fungal infections. MAIN OUTCOME MEASURES: Cure confirmed by culture and microscopy for skin and by culture for nails in patients with clinically diagnosed fungal infections. RESULTS: Of 126 trials identified in 121 papers, 72 (57.1%) met the inclusion criteria. Placebo controlled trials yielded pooled relative risks of failure to cure skin infections: allylamines (0.30, 95% confidence interval 0.24 to 0.38); azoles (0.54, 0.42 to 0.68); undecenoic acid (0.28, 0.11 to 0.74); and tolnaftate (0.46, 0.17 to 1.22). Although meta-analysis of 11 trials comparing allylamines and azoles showed a relative risk of failure to cure of 0.88 (0.78 to 0.99) in favour of allylamines, there was evidence of language bias. Seven reports in English favoured allylamines (0.79, 0.69 to 0.91), but four reports in foreign languages showed no difference between the two drugs (1.01, 0.90 to 1.13). Neither trial of nail infections showed significant differences between alternative topical treatments. CONCLUSIONS: Allylamines, azoles, and undecenoic acid were efficacious in placebo controlled trials. There are sufficient comparative trials to judge relative efficacy only between allylamines and azoles. Allylamines cure slightly more infections than azoles but are much more expensive than azoles. The most cost effective strategy is first to treat with azoles or undecenoic acid and to use allylamines only if that fails

Pragmatic cluster randomised controlled trial of contextualised grammar teaching and small group teaching to improve the writing skills of 11 year old children

Introduction: We evaluated two interventions: a contextualised grammar teaching intervention – Grammar for Writing - to assess whether it improved 11 year old children’s writing skills; and a small group literacy intervention to assess whether or not this was effective. Design and method: We used a pragmatic cluster randomised trial with partial split plot design. Independent concealed randomisation was undertaken at the class level, and, within the intervention group, children were also individually randomised to receive the whole class intervention plus a small group intervention or to receive the intervention in a whole class setting only. The main outcomes were writing and reading assessed by the Progress in English 11 (Long Form) test (GL Assessment). Results: In 2013, 55 schools in England, each with two classes, were recruited and randomised. Within each school, the two classes were randomly allocated to receive either the intervention or the control condition. After randomisation, 2 schools withdrew, leaving 53 schools, 106 classes and 2510 pupils. We observed an effect size (ES) of 0.10 favouring the Grammar for Writing classes; however, this was not statistically significant (95% confidence interval (CI) -0.10 to 0.31). Pupils randomised to the small groups had an increased literacy score when compared with the control classes (ES = 0.24, 95% CI 0.00 to 0.49) and when compared with the intervention children taught in the whole class (ES = 0.21, 95% CI 0.04 to 0.38). Conclusion: There is little evidence that this form of contextualised grammar teaching had an effect on 11 year old children’s writing skills. There was some evidence of an effect for small group teaching

Pressure relieving support surfaces (PRESSURE) trial : cost effectiveness analysis

Objective To assess tire cost effectiveness of alternating pressure mattresses compared with alternating pressure overlays for the prevention of pressure ulcers in patients admitted to hospital. Design Cost effectiveness analysis carried out alongside the pressure relieving support surfaces (PRESSURE) trial; a multicentre UK based pragmatic randomised controlled trial. Setting 11 hospitals in six UK NHS trusts. Participants Intention to treat population comprising 1971 participants. Main outcome measures Kaplan Meier estimates of restricted mean time to development of pressure ulcers and total costs for treatment in hospital. Results Alternating pressure mattresses were associated with lower overall costs (283.6 pound per patient on average, 95% confidence interval -377.59 pound to. 976.79) pound mainly due to reduced length of stay in hospital, and greater benefits (a delay in time to ulceration of 10.64 days on average, - 24.40 to 3.09). The differences in health benefits and total costs for hospital stay between alternating pressure mattresses and alternating pressure overlays were not statistically significant; however, a cost effectiveness acceptability curve indicated that on average alternating pressure mattresses compared with alternating pressure overlays were associated with air 80% probability of being cost saving. Conclusion Alternating pressure mattresses for the prevention of pressure ulcers are more likely to be cost effective and are more acceptable to patients than alternating pressure overlays

Cost effectiveness analysis of larval therapy for leg ulcers

Objective: To assess the cost effectiveness of larval therapy compared with hydrogel in the management of leg ulcers. Design: Cost effectiveness and cost utility analyses carried out alongside a pragmatic multicentre, randomised, open trial with equal randomisation. Population: Intention to treat population comprising 267 patients with a venous or mixed venous and arterial ulcers with at least 25% coverage of slough or necrotic tissue. Interventions: Patients were randomly allocated to debridement with bagged larvae, loose larvae, or hydrogel. Main outcome measure: The time horizon was 12 months and costs were estimated from the UK National Health Service perspective. Cost effectiveness outcomes are expressed in terms of incremental costs per ulcer-free day (cost effectiveness analysis) and incremental costs per quality adjusted life years (cost utility analysis). Results: The larvae arms were pooled for the main analysis. Treatment with larval therapy cost, on average, 96.70 pound ((sic)109.61; $140.57) more per participant per year (95% confidence interval -491.9 pound to 685.8) pound than treatment with hydrogel. Participants treated with larval therapy healed, on average, 2.42 days before those in the hydrogel arm (95% confidence interval -0.95 to 31. 91 days) and had a slightly better health related quality of life, as the annual difference in QALYs was 0.011 (95% confidence interval -0.067 to 0.071). However, none of these differences was statistically significant. The incremental cost effectiveness ratio for the base case analysis was estimated at 8826 pound per QALY gained and 40 pound per ulcer-free day. Considerable uncertainty surrounds the outcome estimates. Conclusions: Debridement of sloughy or necrotic leg ulcers with larval therapy is likely to produce similar health benefits and have similar costs to treatment with hydrogel. Trial registration: Current Controlled Trials ISRCTN55114812 and National Research Register N0484123692

Larval therapy for leg ulcers (VenUS II) : randomised controlled trial

Objective To compare the clinical effectiveness of larval therapy with a standard debridement technique (hydrogel) for sloughy or necrotic leg ulcers. Design Pragmatic, three armed randomised controlled trial. Setting Community nurse led services, hospital wards, and hospital outpatient leg ulcer clinics in urban and rural settings, United Kingdom. Participants 267 patients with at least one venous or mixed venous and arterial ulcer with at least 25% coverage of slough or necrotic tissue, and an ankle brachial pressure index of 0.6 or more. Interventions Loose larvae, bagged larvae, and hydrogel. Main outcome measures The primary outcome was time to healing of the largest eligible ulcer. Secondary outcomes were time to debridement, health related quality of life (SF-12), bacterial load, presence of meticillin resistant Staphylococcus aureus, adverse events, and ulcer related pain (visual analogue scale, from 0 mm for no pain to 150 mm for worst pain imaginable). Results Time to healing was not significantly different between the loose or bagged larvae group and the hydrogel group (hazard ratio for healing using larvae v hydrogel 1.13, 95% confidence interval 0.76 to 1.68; P=0.54). Larval therapy significantly reduced the time to debridement (2.31, 1.65 to 3.2; P<0.001). Health related quality of life and change in bacterial load over time were not significantly different between the groups. 6.7% of participants had MRSA at baseline. No difference was found between larval therapy and hydrogel in their ability to eradicate MRSA by the end of the debridement phase (75% (9/12) v 50% (3/6); P=0.34), although this comparison was underpowered. Mean ulcer related pain scores were higher in either larvae group compared with hydrogel (mean difference in pain score: loose larvae v hydrogel 46.74 (95% confidence interval 32.44 to 61.04), P<0.001; bagged larvae v hydrogel 38.58 (23.46 to 53.70), P<0.001). Conclusions Larval therapy did not improve the rate of healing of sloughy or necrotic leg ulcers or reduce bacterial load compared with hydrogel but did significantly reduce the time to debridement and increase ulcer pain. Trial registration Current Controlled Trials ISRCTN55114812 and National Research Register N0484123692

Subversion of allocation concealment in a randomised controlled trial : a historical case study

BACKGROUND: If the randomisation process within a trial is subverted, this can lead to selection bias that may invalidate the trial's result. To avoid this problem, it is recommended that some form of concealment should be put into place. Despite ongoing anecdotal concerns about their susceptibility to subversion, a surprising number of trials (over 10%) still use sealed opaque envelopes as the randomisation method of choice. This is likely due in part to the paucity of empirical data quantifying the potential effects of subversion. In this study we report a historical before and after study that compares the use of the sealed envelope method with a more secure centralised telephone allocation approach in order to provide such empirical evidence of the effects of subversion. METHODS: This was an opportunistic before and after study set within a multi-centre surgical trial, which involved 654 patients from 28 clinicians from 23 centres in the UK and Ireland. Two methods of randomly allocating subjects to alternative treatments were adopted: (a) a sealed envelope system administered locally, and (b) a centralised telephone system administered by the trial co-ordination centre. Key prognostic variables were compared between randomisation methods: (a) age at trial entry, a key prognostic factor in the study, and (b) the order in which 'randomisation envelopes' were matched to subjects. RESULTS: The median age of patients allocated to the experimental group with the sealed envelope system, was significantly lower both overall (59 vs 63 years, p < 0.01) and in particular for three clinicians (57 vs 72, p < 0.01; 33 vs 69, p < 0.001; 47 vs 72, p = 0.03). No differences in median age were found between the allocation groups for the centralised system. CONCLUSIONS: Due to inadequate allocation concealment with the sealed envelope system, the randomisation process was corrupted for patients recruited from three clinicians. Centralised randomisation ensures that treatment allocation is not only secure but seen to be secure. Where this proves to be impossible, allocation should at least be performed by an independent third party. Unless it is an absolute requirement, the use of sealed envelopes should be discontinued forthwith