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Persistence, reproducibility, and cost-effectiveness of an intervention to improve the quality of osteoporosis care after a fracture of the wrist: results of a controlled trial |
Majumdar S R, Johnson J A, Lier D A, Russell A S, Hanley D A, Blitz S, Steiner I P, Maksymowych W P, Morrish D W, Holroyd B R, Rowe B H |
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Record Status This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn. Health technology The study compared a pragmatic osteoporosis quality improvement intervention directed at older patients with a fracture of the wrist and their primary care physicians against usual care. The intervention consisted of physician reminders, local opinion leader endorsed treatment guidelines, and patient education. A description of usual care was not reported in the present paper.
Study population The study population comprised patients aged 50 years or older with a fracture of the wrist. Patients who had already been treated for osteoporosis were excluded.
Setting The setting was secondary care (emergency department). The economic study was carried out in Canada.
Dates to which data relate The effectiveness and resource use data from the original study were obtained between January 2001 and September 2002. The effectiveness data used in the model were taken from published studies dating from 2000 to 2004. The cost data were taken from sources dated 2003 to 2004. The price year was 2004.
Source of effectiveness data The primary health outcomes assessed in the review were the rate of starting an osteoporosis-indicated prescription medication (bisphosphonates, raloxifene, calcitonin, or hormone therapy) within 6 months of fracture, and the rate of persistence with osteoporosis treatment and reproducibility of the intervention effect at 1 year post-fracture.
The secondary outcomes were:
receipt of a bone mineral density test,
the annual fracture rate for low bone mass patients,
the reduction in fracture risk with treatment,
the mortality rate, and
age-specific quality of life weights.
Modelling A Markov state-transition model was developed to simulate the osteoporosis experience of a cohort of 100 women with wrist fractures similar to those in the original study but followed over their lifetime horizon (i.e. from age 66 until 100 years or death). The Markov model included a healthy state, four other health states (hip fracture, post-hip fracture, spine fracture and wrist fracture) and one "dead" state. The duration of each cycle was 1 year. The three Markov processes constructed corresponded to low bone mass patients receiving osteoporosis treatment (M1), low bone mass patients not receiving treatment (M2), and normal bone mass (M3). The model was based on various assumptions about efficacy, transition probabilities and costs. Such assumptions were all reported in the study but are too numerous to be reported in full in this abstract.
Sources searched to identify primary studies The primary outcome was derived from a single-centred, non-randomised controlled trial with a 1-year follow-up period (Majumdar et al. 2004, see 'Other Publications of Related Interest' below for bibliographic details). Other outcomes assessed in the review were derived mostly from a published study (Johnell et al. 2003, see 'Other Publications of Related Interest' below for bibliographic details). A systematic review and meta-analysis and a large Canadian cohort study were also used to assess fracture rate estimates. A series of systematic reviews was used to assess the estimated reduction in fracture risk with alendronate.
Methods used to judge relevance and validity, and for extracting data The sources searched for primary studies were not reported. The criteria used to ensure the validity of the primary studies were not reported. No methods to assess the validity of the primary studies appear to have been used. Where data were limited, conservative assumptions were made.
Measure of benefits used in the economic analysis The benefit measure used was the quality-adjusted life-years (QALYs). Quality of life weights were taken from a published source (Johnell et al. 2003). The instrument used to assess the utility values was not reported. The authors also reported the number of fractures avoided.
Direct costs The direct costs to the health care payer were included in this study. Different categories of costs were investigated. Specifically, a one-time intervention cost (i.e. identifying eligible patient, producing and delivering physician and patient materials, patient counselling and facility overhead), the cost of osteoporosis treatment (including alendronate at 70 mg per week and one annual physician visit), and the cost of subsequent fractures (including inpatient care, emergency visit, outpatient rehabilitation, home care and physician visits).
The costs and the quantities were reported separately. Resource use was directly analysed from the study patients. The costs of subsequent fractures were derived from data relating to health service use and unit values obtained from regional and national databases. Fees for all physician services were obtained from the Alberta fee schedule. The unit costs were taken from a number of published sources in Canada. Discounting was carried out at an annual rate of 3%. The price year was 2004.
Statistical analysis of costs Although the authors seem to have had individual patient data for the costs, no statistical analysis of the costs was performed.
Indirect Costs No productivity costs were included.
Currency Canadian dollars (CAD). The conversion rates to US dollars ($) and euros (EUR) were $1 = CAD 0.71 and EUR 1 = CAD 0.63.
Sensitivity analysis One-way sensitivity analyses were undertaken on baseline assumptions and parameter estimates (e.g. intervention costs, rate of treatment persistence, risk of re-fracture for patients with normal bone mass, osteoporosis costs, duration of treatment and discount rate). In addition, a multi-way sensitivity analysis was conducted by varying the intervention costs, treatment costs and treatment duration to evaluate "worst-case" and "best-case" scenarios.
Estimated benefits used in the economic analysis Over the lifetime horizon, the rate of hip re-fracture was 0.133 in the intervention group and 0.141 in the control group. The rate of total re-fractures was 0.913 (intervention group) and 0.956 (control group), respectively. Approximately one hip fracture and four total fractures were avoided in patients exposed to the intervention.
The mean QALYs were 9.504 for the intervention group and 9.492 for the control group. The number of QALYs gained with the intervention was 0.012.
Cost results The average cost per patient in the intervention group was CAD 11,067 over the lifetime horizon. The average cost per patient in the control group was CAD 11,080.
The intervention was associated with a small incremental cost-saving of CAD 13 ($9) per patient.
Synthesis of costs and benefits The costs and benefits were combined to give an incremental cost per QALY gained.
The intervention was a dominant strategy as it cost less and added more QALYs than usual care. The incremental savings per QALY gained were CAD 1,083.
The sensitivity analysis showed that the results were robust. The base-case results were most sensitive to assumptions about treatment costs: a 50% increase in the price of alendronate led to an incremental cost of CAD 24,250 per QALY gained. In the multi-way sensitivity analysis, the worst-case scenario yielded an incremental ratio of CAD 27,583 per QALY gained, whereas the best-case scenario yielded an incremental cost-saving of CAD 469 per patient exposed to the intervention.
Authors' conclusions The pragmatic quality improvement intervention directed at patients and their physicians led to substantial improvements in osteoporosis treatment, even when delivered 6-month post-fracture. From the health care payer's perspective, the intervention appears to have led to both cost-savings and gains in life expectancy compared with usual care.
CRD COMMENTARY - Selection of comparators Although no explicit justification was given for using usual care as the comparator, it would appear to represent current practice in the authors' settings. You should decide if the comparator used represents current practice in your own setting. Validity of estimate of measure of effectiveness The direct effectiveness data for the intervention came from a single study. Although randomised controlled trials are considered to be the 'gold' standard study design when comparing health care interventions, the present study design, a non-randomised controlled trial, appears to have been appropriate for the hypothesis. Power calculations were not performed, but blinded assessment was reported. The authors did not clearly state whether the study sample was representative of the study population. The patient groups are likely to have been comparable at baseline, although no statistical analysis was reported. There was also another source of effectiveness data. A decision analytic model was constructed to extend the horizon of the initial study over the patients' lifetime. The parameters used in the model were derived from published research. The paper stated that a series of systematic reviews was used. The authors provided very few details of the methods used in their review of the literature. It was not stated how the results from the literature and trials were combined to give estimates of parameters. In addition, the impact of differences between the identified studies was not taken into account when estimating effectiveness. Some estimates of effectiveness were based on authors' assumptions. However, the authors did not provide any justification for their choice of assumptions. Sensitivity analyses were conducted to improve the internal validity of the study. Validity of estimate of measure of benefit The estimation of health benefit (QALYs) was derived appropriately using a Markov model. The benefits were appropriately discounted. The utilities used to derive QALYs were taken from the published literature, but no details of the valuation methods were given. Validity of estimate of costs The analysis of the costs was performed from the perspective of the health care payer. All the relevant categories of costs, as well as all relevant major costs, appear to have been included in the analysis. The cost quantities were derived from the study patients and the unit costs from national sources. The price year was appropriately reported, which will aid any future inflation exercises. Since the costs were incurred during a long time, discounting was relevant and was performed appropriately. The authors undertook a series of one-way sensitivity analyses in which they varied intervention and treatment costs. They also reported the unit costs and the resource quantities separately, which will enhance the generalisability of the results. Other issues The authors did not compare their results with those from other relevant studies. The issue of generalisability to other settings was partially addressed in the sensitivity analysis. The authors do not appear to have presented their results selectively and the results reflected the scope of the analysis. The authors reported a number of further limitations to their study. For example, the non-randomised study design, the small sample size, the lack of statistical power to detect differences in fracture rates, and the fact that most of the assumptions probably underestimated the true cost-effectiveness. Implications of the study The authors did not make any recommendations for further research or changes to practice.
Source of funding Funded by the Alberta Medical Association, Alberta Health and Wellness, and the Alberta Heritage Foundation for Medical Research.
Bibliographic details Majumdar S R, Johnson J A, Lier D A, Russell A S, Hanley D A, Blitz S, Steiner I P, Maksymowych W P, Morrish D W, Holroyd B R, Rowe B H. Persistence, reproducibility, and cost-effectiveness of an intervention to improve the quality of osteoporosis care after a fracture of the wrist: results of a controlled trial. Osteoporosis International 2007; 18(3): 261-270 Other publications of related interest Because readers are likely to encounter and assess individual publications, NHS EED abstracts reflect the original publication as it is written, as a stand-alone paper. Where NHS EED abstractors are able to identify positively that a publication is significantly linked to or informed by other publications, these will be referenced in the text of the abstract and their bibliographic details recorded here for information.
Majumdar SR, Rowe BH, Folk D, et al. A controlled trial to increase detection and treatment of osteoporosis in older patients with a wrist fracture. Ann Intern Med 2004;141:366-73.
Johnell O, Jonsson B, Jonsson L, et al. Cost effectiveness of alendronate for the treatment of osteoporosis and prevention of fractures. Pharmacoeconomics 2003;21:305-14.
Indexing Status Subject indexing assigned by NLM MeSH Aged; Aged, 80 and over; Alberta; Bone Density Conservation Agents /economics /therapeutic use; Cost-Benefit Analysis; Epidemiologic Methods; Female; Fractures, Bone /economics /etiology /prevention & Health Care Costs /statistics & Humans; Male; Middle Aged; Osteoporosis /complications /drug therapy /economics; Osteoporosis, Postmenopausal /complications /drug therapy /economics; Patient Compliance /statistics & Quality of Health Care; Quality of Life; Treatment Outcome; Wrist Injuries /economics /etiology; control; numerical data; numerical data AccessionNumber 22007000347 Date bibliographic record published 31/01/2008 Date abstract record published 31/01/2008 |
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