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Shoulder arthroplasty with or without resurfacing of the glenoid in patients who have osteoarthritis |
Gartsman G M, Roddey T S, Hammerman S M |
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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 total shoulder arthroplasty against hemiarthroplasty in the treatment of patients with osteoarthritis of the shoulder.
Economic study type Cost-effectiveness analysis.
Study population The study population comprised patients with a pain in the shoulder due to osteoarthritis that had been unresponsive to medical treatment and that interfered with activities of daily living.
Setting The setting was secondary care. The economic study was carried out in the Texas Orthopaedic Hospital in Houston, USA.
Dates to which data relate The effectiveness and resource data were collected between December 1992 and December 1996. The price year was 1999.
Source of effectiveness data The effectiveness data were derived from a single study.
Link between effectiveness and cost data Cost data were prospectively collected from the same patient sample as that used in the effectiveness analysis.
Study sample The authors reported that a power analysis was performed to determine the sample size necessary to demonstrate a difference resulting from the use of a glenoid component in shoulder operations. An effect size of 0.60 was estimated for this study. The necessary sample size, for an effect size of 0.60, one-tailed analysis and power of 0.80, was approximately 35 subjects per group. A total of 134 consecutive shoulders in 124 patients were evaluated for inclusion in the study. Of these, 71 patients (77 shoulders) met one criterion for exclusion from the study. 53 patients (57 shoulders) who met criteria for inclusion were asked to participate in the study, and 51 patients (55 shoulders) agreed. Of the 51 patients 27 were randomly assigned to receive total shoulder arthroplasty and 24 to receive hemiarthroplasty. The authors reported that the criteria for inclusion in the study were a diagnosis of osteoarthritis, an intact rotator cuff, and a concentric glenoid. A diagnosis other than osteoarthritis was a criterion for exclusion.
Study design The study was a single-centred, prospective, randomised, controlled trial carried out in the Texas Orthopaedic Hospital in Houston. Patients were randomly assigned, according to a random numbers table, to one of two groups: total shoulder arthroplasty, or hemiarthroplasty. The duration of follow-up was 35 months. Four patients were lost to follow-up, thus leaving 47 patients for analysis (51 shoulders). The authors reported that analysis of the data was masked to knowledge of the patients' names or identification numbers. The authors did not report if this meant the analysts were masked to the treatment allocation of the patients.
Analysis of effectiveness The analysis was based on treatment completers only. The primary outcomes used in the analysis were as follows:
The University of California at Los Angeles shoulder scale. This is a 35 point scale with a maximum of ten points assigned for pain, 10 points for function, and 5 points each for motion, strength, and patient satisfaction.
The American Shoulder and Elbow Surgeons shoulder index. This was calculated with the use of scores that the patient assigns for pain on a 10-point visual analogue scale, and the use of scores that the patient assigns for 10 self-assessed activities of daily living.
The patient groups were shown to be largely comparable. The twenty-two patients (twenty-four shoulders) who were assigned to hemiarthroplasty had a median age of 64.6 (+/- 6.3, range: 45 - 78) compared to a median age of 65.3 (+/- 8.4, range: 50 - 86), (p=0.724) in the 25 patients (27 shoulders) who received total shoulder arthroplasty. Of the patients who received hemiarthroplasty 13 were male and 9 female, compared to 15 males and 10 females in the patients who received total shoulder arthroplasty, (p=0.845). The authors reported that no significant differences were observed between the two groups with regard to the preoperative American Shoulder and Elbow Surgeons shoulder index, or the University of California at Los Angeles shoulder score, (p>0.0125).
Effectiveness results The authors used a Bonferroni adjustment to estimate the significance level required with multiple comparisons. This was set at p=0.006 for the comparison of postoperative scores.
Both procedures resulted in a significant improvement (p<0.005) in the total shoulder scores when compared with the pre-operative ratings, both according to the American Shoulder and Elbow Surgeons shoulder index scale and to the University of California at Los Angeles Shoulder score.
However, the authors reported that no significant difference between the groups was noted with regard to the postoperative University of California at Los Angeles. The mean score after hemiarthroplasties was 23.2 points (range: 10 - 31 points) compared with a mean score of 27.4 points (range: 9 - 34) after the total shoulder arthroplasties, (p=0.008). With regard to the postoperative American Shoulder and Elbow Surgeons shoulder index there was a mean score of 65.2 points (range: 15 - 94) after the hemiarthroplasties, compared to a mean score of 77.3 points (range: 3 - 300) after the total shoulder arthroplasties, (p=0.057).
A reduction in pain was achieved after both procedures. The difference between the preoperative and postoperative pain scores was significant (p<0.0005) in both operative groups. However, pain relief after the total shoulder arthroplasties was significantly greater than after the hemiarthroplasties, (p=0.002).
Both procedures resulted in a significant improvement in satisfaction when compared with the preoperative rating, (p<0.0005). Although the patients who underwent total shoulder arthroplasty demonstrated more satisfaction than those who underwent a hemiarthroplasty, the difference was not significant.
Both procedures resulted in a significant improvement in the range of motion compared with the preoperative rating, (p<0.0005). However, the authors reported that no difference between the two groups was observed in relation to the University of California at Los Angeles range-of-motion score, (p=0.614).
Both procedures resulted in an improvement in strength compared with the preoperative rating, (p<0.0005). No significant difference in the postoperative strength scores was noted between the two groups of patients, (p=0.441).
Clinical conclusions The authors concluded that total shoulder arthroplasty provides superior pain relief when compared to hemiarthroplasty.
Measure of benefits used in the economic analysis No summary measure of health benefit was used in the economic analysis. The outcomes were reported in a disaggregated way and, as such, this was a cost-consequences study.
Direct costs The authors did not report resource use and prices separately. The following direct costs were included in the analysis: the cost of a glenoid component($600); the cost of a bone cement ($177); the cost of increased hospital charges for the longer operative time (35 minutes) that was required for a total shoulder arthroplasty ($400). The authors did not report whether discounting was undertaken. The price year was 1999.
Statistical analysis of costs No statistical analysis of costs was conducted.
Indirect Costs No indirect costs were included in the analysis.
Currency US dollars ($). No currency conversions were reported.
Sensitivity analysis No sensitivity analysis was reported.
Estimated benefits used in the economic analysis The reader is referred to the effectiveness results reported earlier.
Cost results The authors reported that total shoulder arthroplasty resulted in an increase in cost of $1,177 above that of hemiarthroplasty. In total the twenty-seven index arthroplasties cost $31,779 more than the twenty-four index hemiarthroplasties. However, three of the twenty-four hemiarthroplasties required revision operations for the insertion of a glenoid component at a total cost $47,994 ($15,998 each) within the 12 month follow-up period.
Synthesis of costs and benefits Cost and benefits were not combined and no additional incremental analysis was reported.
Authors' conclusions The authors concluded that total shoulder arthroplasty provided superior pain relief when compared to hemiarthroplasty in the treatment of patients with glenohumeral osteoarthritis, but was associated with an increased cost of $1,177 per patient.
CRD COMMENTARY - Selection of comparators A justification was given for the choice of comparator used, namely that it represented common practice in the authors' setting. You, as a user of this database, should decide if this is a widely used health technology in your own setting.
Validity of estimate of measure of effectiveness The analysis was based on a single-centred, prospective, randomised, controlled trial that was appropriate for the study question. The study sample was representative of the study population, and patient groups were largely shown to be comparable at analysis. Appropriate statistical analyses were undertaken to take account of multiple hypothesis testing. However, the authors did not report details of the method of patient selection or of patients who refused to participate in the trial. The authors used random numbers tables kept by the operating theatre nurse to assign patients to a treatment group. Patients with odd numbers received hemiarthroplasty and those with an even number received total shoulder arthroplasty. This is a relatively weak randomisation method and may have led to bias in patient treatment allocation. The health care professionals and patients were not masked to treatment allocation, which could have biased their responses to the outcome assessments used. The data analysts were masked to the patients' identities. However, the authors stated that the study would have been improved through the use of an independent evaluator who was not aware of the type of operation performed.
The authors reported a number of limitations to their study, including the small number of patients, which was less than that indicated by the power calculations. The authors stated that, although sufficient data were obtained to observe significant differences it is possible that the sample size was inadequate to differentiate the effect of the type of operation. The authors also reported a limitation to the study in relation to the spread of the 95% confidence intervals. The authors reported that one interpretation of the data is that the scoring systems used do not measure the status of the patient with sufficient accuracy. The authors recognised that the present scoring system may not optimally measure the outcome of shoulder arthroplasty.
Validity of estimate of measure of benefit The authors did not derive a summary measure of health benefit. The analysis was therefore categorised as a cost-consequences study.
Validity of estimate of costs The authors did not fully report the direct costs included in the analysis and did not state whether the study was based on unit cost or on charge data. The authors did not report resource use and prices separately. Consequently it is not possible to establish whether some costs were omitted from the analysis, and the extent to which these are likely to have affected the authors' conclusions. Costs and quantities were not reported separately. A statistical analysis of quantities was performed, however no statistical analysis of prices was conducted. The authors reported no sensitivity analysis of quantities or prices. The authors reported no currency conversions and discounting was not undertaken.
Other issues The authors made appropriate comparisons of their findings with those from other studies, but did not address the issue of generalisability to other settings.
Implications of the study The authors concluded that total shoulder arthroplasty provides superior pain relief when compared to hemiarthroplasty in the treatment of patients with glenohumeral osteoarthritis, but is associated with an increased cost of $1,177 per patient. Moreover, the authors also state that whilst hemiarthroplasty has the advantages of decreased complexity, operating time and cost, three of the twenty-four shoulders required a revision operation for the insertion of a glenoid component at a total cost of $47,994.
Bibliographic details Gartsman G M, Roddey T S, Hammerman S M. Shoulder arthroplasty with or without resurfacing of the glenoid in patients who have osteoarthritis. Journal of Bone and Joint Surgery. American volume 2000; 82A(1): 26-34 Indexing Status Subject indexing assigned by NLM MeSH Aged; Arthroplasty, Replacement /economics /methods; Costs and Cost Analysis; Female; Hospital Charges; Humans; Male; Middle Aged; Osteoarthritis /diagnosis /radiography /surgery; Postoperative Complications; Range of Motion, Articular; Research Support, Non-U.S. Gov't; Shoulder Joint /physiopathology /radiography /surgery AccessionNumber 22000000195 Date bibliographic record published 30/04/2002 Date abstract record published 30/04/2002 |
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