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Gask L, Dowrick C, Dixon C, Sutton C, Perry R, Torgerson D, Usherwood T. A pragmatic cluster randomized controlled trial of an educational intervention for GPs in the assessment and management of depression. Psychol Med 2004; 34:63-72. [PMID: 14971627 DOI: 10.1017/s0033291703001065] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND General practitioners (GPs) can be provided with effective training in the skills to manage depression. However, it remains uncertain whether such training achieves health gain for their patients. METHOD The study aimed to measure the health gain from training GPs in skills for the assessment and management of depression. The study design was a cluster randomized controlled trial. GP participants were assessed for recognition of psychological disorders, attitudes to depression, prescribing patterns and experience of psychiatry and communication skills training. They were then randomized to receive training at baseline or the end of the study. Patients selected by GPs were assessed at baseline, 3 and 12 months. The primary outcome was depression status, measured by HAM-D. Secondary outcomes were psychiatric symptoms (GHQ-12) quality of life (SF-36), satisfaction with consultations, and health service use and costs. RESULTS Thirty-eight GPs were recruited and 36 (95%) completed the study. They selected 318 patients, of whom 189 (59%) were successfully recruited. At 3 months there were no significant differences between intervention and control patients on HAM-D, GHQ-12 or SF-36. At 12 months there was a positive training effect in two domains of the SF-36, but no differences in HAM-D, GHQ-12 or health care costs. Patients reported trained GPs as somewhat better at listening and understanding but not in the other aspects of satisfaction. CONCLUSIONS Although training programmes may improve GPs' skills in managing depression, this does not appear to translate into health gain for depressed patients or the health service.
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Bagnall AM, Jones L, Ginnelly L, Lewis R, Glanville J, Gilbody S, Davies L, Torgerson D, Kleijnen J. A systematic review of atypical antipsychotic drugs in schizophrenia. Health Technol Assess 2003; 7:1-193. [PMID: 12925268 DOI: 10.3310/hta7130] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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Brealey S, Burton K, Coulton S, Farrin A, Garratt A, Harvey E, Letley L, Martin J, Klaber MJ, Russell I, Torgerson D, Underwood M, Vickers M, Whyte K, Williams M. UK Back pain Exercise And Manipulation (UK BEAM) trial--national randomised trial of physical treatments for back pain in primary care: objectives, design and interventions [ISRCTN32683578]. BMC Health Serv Res 2003; 3:16. [PMID: 12892566 PMCID: PMC194218 DOI: 10.1186/1472-6963-3-16] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2003] [Accepted: 08/01/2003] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Low back pain has major health and social implications. Although there have been many randomised controlled trials of manipulation and exercise for the management of low back pain, the role of these two treatments in its routine management remains unclear. A previous trial comparing private chiropractic treatment with National Health Service (NHS) outpatient treatment, which found a benefit from chiropractic treatment, has been criticised because it did not take treatment location into account. There are data to suggest that general exercise programmes may have beneficial effects on low back pain. The UK Medical Research Council (MRC) has funded this major trial of physical treatments for back pain, based in primary care. It aims to establish if, when added to best care in general practice, a defined package of spinal manipulation and a defined programme of exercise classes (Back to Fitness) improve participant-assessed outcomes. Additionally the trial compares outcomes between participants receiving the spinal manipulation in NHS premises and in private premises. DESIGN Randomised controlled trial using a 3 x 2 factorial design. METHODS We sought to randomise 1350 participants with simple low back pain of at least one month's duration. These came from 14 locations across the UK, each with a cluster of 10-15 general practices that were members of the MRC General Practice Research Framework (GPRF). All practices were trained in the active management of low back pain. Participants were randomised to this form of general practice care only, or this general practice care plus manipulation, or this general practice care plus exercise, or this general practice care plus manipulation followed by exercise. Those randomised to manipulation were further randomised to receive treatment in either NHS or private premises. Follow up was by postal questionnaire one, three and 12 months after randomisation. The primary analysis will consider the main treatment effects before interactions between the two treatment packages. Economic analysis will estimate the cost per unit of health utility gained by adding either or both of the treatment packages to general practice care.
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Torgerson D, Lampo M, Wo PT. Ability of cellulose acetate and polyacrylamide enzyme electrophoresis to separate 13 species of phlebotomine sand flies (Diptera: Psychodidae) from Venezuela. JOURNAL OF MEDICAL ENTOMOLOGY 2001; 38:501-509. [PMID: 11476329 DOI: 10.1603/0022-2585-38.4.501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The detection of cryptic species by biochemical methods indicates that within the phlebotomine fauna morphological data are not always adequate for species diagnosis. Cellulose acetate and polyacrylamide enzyme electrophoresis methods were compared for their effectiveness in identifying 13 species of Venezuelan phlebotomine sand flies and resolving alleles. Eight diagnostic loci unambiguously separated these 13 species of sand flies. Although acrylamide was as effective as cellulose acetate in species separation, differences were detected in the resolution of some alleles. Cellulose acetate identified more alleles at Ak and Fum, and resolved better at Pgm, whereas acrylamide identified more alleles at Gpi, Mdh, and Me. Therefore, erroneous species diagnoses may occur, if diagnostic loci detected by one technique are used by a second technique without adequate reference standards.
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Iglesias C, Torgerson D. Does length of questionnaire matter? A randomised trial of response rates to a mailed questionnaire. J Health Serv Res Policy 2000; 5:219-21. [PMID: 11184958 DOI: 10.1177/135581960000500406] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To assess whether length of questionnaire affects response rates. METHODS A quasi-randomised trial of women aged 70 years and over in a general practice in England. Three questionnaires of different lengths: a clinical questionnaire (four pages); the same questionnaire plus the EuroQol (five pages); the same questionnaire plus the SF-12 (seven pages). The impact of length on the proportion of returned questionnaires and item completion rates was assessed. RESULTS In total, 847 questionnaires were mailed; response rates were 49%, 49% and 40% to the short, medium and long questionnaires, respectively. This difference was statistically significant when the short questionnaire was compared against the longest instrument (9% difference; 95% confidence interval (CI) of difference = 0.3% to 16.6%). Item completion rates for the clinical questionnaire did not differ. Respondents did not differ in age or self-reported health status between the three groups. CONCLUSIONS Increasing the length of a questionnaire from five to seven pages reduces response rates from women aged 70 years and over. However, lengthening a questionnaire does not seem to affect the quality of responses to questions near the front of the questionnaire.
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Iglesias C, Torgerson D. Expenditure. Beyond compare. THE HEALTH SERVICE JOURNAL 2000; 110:35. [PMID: 11184382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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Cameron I, Crotty M, Currie C, Finnegan T, Gillespie L, Gillespie W, Handoll H, Kurrle S, Madhok R, Murray G, Quinn K, Torgerson D. Geriatric rehabilitation following fractures in older people: a systematic review. Health Technol Assess 2000; 4:i-iv, 1-111. [PMID: 10702905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
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Bradley M, Cullum N, Nelson EA, Petticrew M, Sheldon T, Torgerson D. Systematic reviews of wound care management: (2). Dressings and topical agents used in the healing of chronic wounds. HEALTH TECHNOLOGY ASSESSMENT (WINCHESTER, ENGLAND) 2000. [PMID: 10683589 DOI: 10.3310/hta31720] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Bradley M, Cullum N, Nelson EA, Petticrew M, Sheldon T, Torgerson D. Systematic reviews of wound care management: (2). Dressings and topical agents used in the healing of chronic wounds. Health Technol Assess 2000; 3:1-35. [PMID: 10683589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
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Abstract
OBJECTIVES The objectives of this study were twofold. The first was to compare characteristics of responders and non-responders to a survey of women attending a bone mineral density screening service in Aberdeen concerned with the screening process which contained questions on attenders' willingness to pay (WTP) and willingness to wait (WTW) for screening. The second objective was to compare the characteristics of those responding to either the WTP or the WTW questions relative to those who responded to both. METHODS After receiving a scan, women completed the questionnaire at the clinic or returned it by post. Logistic regression analysis was used to compare the characteristics of the responders and non-responders. RESULTS Those who smoked were less likely to return the questionnaire, whilst those who drank alcohol were more likely to return it. The majority of respondents answered both WTP and WTW questions. The proportions responding to the WTW and WTP questions were 93.2% and 81.5% for the two questions, respectively (95% confidence interval of difference = 9.4% to 13.9%). The only result which was statistically significant at the 1% level showed that, relative to those who answered the WTW but not the WTP questions, those who answered both were more likely to be older when they left full-time education. A weaker statistical association (at the 5% level) revealed that those who were older when leaving full-time education were more likely to answer a WTP question than not. CONCLUSIONS WTP questions seem to be less acceptable to those who leave full-time education earlier. Analysts may need to account for this in future studies. Whether such results can be replicated and reasons for non-response should be investigated.
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Crawford F, Hart R, Bell-Syer S, Torgerson D, Young P, Russell I. Topical treatments for fungal infections of the skin and nails of the foot. Cochrane Database Syst Rev 2000:CD001434. [PMID: 10796792 DOI: 10.1002/14651858.cd001434] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVES The objective of this review is to identify and evaluate the evidence of efficacy for topical treatments for fungal infections of the skin and nails of the human foot. To establish the effectiveness of topical treatments in achieving a cured condition and in preventing recurrence SEARCH STRATEGY Randomised controlled trials were identified from the MEDLINE, EMBASE and CINHAL databases, from the beginning of these databases to December 1997. Also we screened the Cochrane Controlled Trials Register, the Science Citation Index BIOSIS, CAB - Health, Healthstar and Economic databases. References and unpublished studies were searched, podiatry journals handsearched and the pharmaceutical industry contacted. SELECTION CRITERIA Only randomised controlled trials (RCTs) using participants who have mycologically diagnosed fungal infections of the skin and nails of the human foot are included in the analysis. DATA COLLECTION AND ANALYSIS Two reviewers independently summarised the included trials and appraised their quality of reporting using a structured data extraction tool which assessed 12 quality criteria. MAIN RESULTS Of 126 trials identified in 121 papers, 72 met the inclusion criteria. Placebo-controlled trials yielded the following pooled relative risks of failure to cure (RRFC) for skin infections: allylamines 0.30 (95% confidence interval 0.23 to 0.37); azoles 0.53 (0.42 to 0.68); undecenoic acid 0.28 (0.11 to 0.74); tolnaftate 0.46 (0.17 to 1.22). Though meta-analysis of 11 trials comparing allylamines and azoles showed an RRFC of 0.88 (0.78 to 0.99) in favour of allylamines, there was evidence of language bias. Seven English language reports favoured allylamines (RRFC = 0.79; 0.68 to 0.93) but four foreign language reports showed no difference between the two drugs (RRFC = 1.00; 0.90 to 1.12). The two trials of nail infections did not provide any evidence of benefit for topical treatments compared with placebo. CONCLUSIONS In placebo-controlled trials allylamines, azoles and undecenoic acid were efficacious. 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. The most cost-effective strategy is first to treat with azoles or undecenoic acid and to use allylamines only if that fails.
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Abstract
The European Foundation for Osteoporosis and Bone Disease (EFFO), the Royal College of Physicians, the European Community and the National Osteoporosis Foundation of the USA (NOF) have recently published guidelines for the diagnosis and management of osteoporosis. All adopt case-finding strategies but the conceptual approach between the European and North American guidelines differs fundamentally. This gives rise to differences in the populations identified for assessment and treatment.
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Lampo M, Torgerson D, Márquez LM, Rinaldi M, García CZ, Arab A. Occurrence of sibling species of Lutzomyia longipalpis (Diptera: Psychodidae) in Venezuela: first evidence from reproductively isolated sympatric populations. Am J Trop Med Hyg 1999; 61:1004-9. [PMID: 10674686 DOI: 10.4269/ajtmh.1999.61.1004] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The delimitation of cryptic species within the main vector of the American visceral leishmaniasis, Lutzomyia longipalpis, remains a topic of controversy. An analysis of genetic variability based on 8 enzymatic loci revealed fixed differences in 2 diagnostic loci, adenylate kinase (Ak) and hexokinase (Hk), between sympatric and allopatric populations at 4 localities in Venezuela. The absence of heterozygotes for these 2 loci within 1 locality indicates, for the first time, the presence of 2 sympatric reproductively isolated populations or cryptic species within L. longipalpis. Significant differences were also detected between these cryptic species in the allele frequencies of glucose-6-phosphate isomerase (Gpi) and malate dehydrogenase, decarboxylating (Me). One species showed mean heterozygosities that ranged between 6.6% and 6.7%, with 1.6-1.9 alleles detected per locus, while the other had mean heterozygosities that ranged from 4.3% to 6.3%, with 1.3-1.6 alleles per locus. Comparisons of isozyme profiles with published data suggests that 1 species is similar to the L. longipalpis described in Colombian and Brazilian populations, whereas the other has not been previously reported.
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Kirby PL, Brady AR, Thompson SG, Torgerson D, Davies AH. The Vein Graft Surveillance Trial: rationale, design and methods. VGST participants. Eur J Vasc Endovasc Surg 1999; 18:469-74. [PMID: 10637141 DOI: 10.1053/ejvs.1999.0822] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVES to compare the amputation rates, quality of life and health care costs in patients receiving duplex ultrasound scanning against clinical surveillance following femoropopliteal and femorocrural vein bypass. DESIGN multi-centre, prospective, randomised controlled trial. METHODS 1200 patients with a patent vein graft at 30 days postoperatively will be randomised to either clinical or duplex follow-up. All patients are seen in an out-patient clinic at 6 weeks, then 3, 6, 9, 12 and 18 months postoperatively. At each appointment patients are examined clinically; palpable pulses in the graft and crural vessels, presenting symptoms and their ankle-branchial pressure indices (ABPIs) measured. In the duplex group only, the results of the scan are monitored. The incidence of radiological and/or surgical interventions throughout the follow-up period are also noted. Quality of life is measured using the SF-36 and EuroQol questionnaires at the 6 and 18 month appointments. Hospital stays and resource use are documented for health economic analysis. RESULTS the primary endpoint of this study is amputation or death from vascular causes; however, graft patency rates will also be compared between the groups. Quality of life and health economic data will be used to determine if there is any benefit in either arm in these outcomes between follow-up strategies. CONCLUSIONS this large, randomised-controlled trial will hopefully provide direct evidence on the benefit of duplex surveillance for vein grafts in terms of limb salvage, quality of life of the patients and cost-benefit to the purchaser.
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Moffett JK, Torgerson D, Bell-Syer S, Jackson D, Llewlyn-Phillips H, Farrin A, Barber J. Randomised controlled trial of exercise for low back pain: clinical outcomes, costs, and preferences. BMJ (CLINICAL RESEARCH ED.) 1999; 319:279-83. [PMID: 10426734 PMCID: PMC28176 DOI: 10.1136/bmj.319.7205.279] [Citation(s) in RCA: 233] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
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.
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Torgerson D, Raftery J. Economics notes: measuring outcomes in economic evaluations. BMJ (CLINICAL RESEARCH ED.) 1999; 318:1413. [PMID: 10334758 PMCID: PMC1115785 DOI: 10.1136/bmj.318.7195.1413] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Byford S, Harrington R, Torgerson D, Kerfoot M, Dyer E, Harrington V, Woodham A, Gill J, McNiven F. Cost-effectiveness analysis of a home-based social work intervention for children and adolescents who have deliberately poisoned themselves. Results of a randomised controlled trial. Br J Psychiatry 1999; 174:56-62. [PMID: 10211152 DOI: 10.1192/bjp.174.1.56] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Little evidence exists regarding the effectiveness or cost-effectiveness of alternative treatment services in the field of child and adolescent psychiatry. AIMS To assess the cost-effectiveness of a home-based social work intervention for young people who have deliberately poisoned themselves. METHOD Children aged < or = 16 years, referred to child mental health teams with a diagnosis of deliberate self-poisoning were randomly allocated to either routine care (n = 77) or routine care plus the social work intervention (n = 85). Clinical and resource-use data were assessed over six months from the date of trial entry. RESULTS No significant differences were found between the two groups in terms of the main outcome measures or costs. In a sub-group of children without major depression, suicidal ideation was significantly lower in the intervention group at the six-month follow-up (P = 0.01), with no significant differences in cost. CONCLUSIONS A family-based social work intervention for children and adolescents who have deliberately poisoned themselves is as cost-effective as routine care alone.
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Gosden T, Pedersen L, Torgerson D. How should we pay doctors? A systematic review of salary payments and their effect on doctor behaviour. QJM 1999; 92:47-55. [PMID: 10209672 DOI: 10.1093/qjmed/92.1.47] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We reviewed the published and unpublished international literature to determine the influence of salaried payment on doctor behaviour. We systematically searched Medline, BIDS Embase, Econlit and BIDS ISI and the reference lists of located papers to identify relevant empirical studies comparing salaried doctors with those paid by alternative methods. Only studies which reported objective outcomes and measures of the behaviour of doctors paid by salary compared to an alternative method were included in the review. Twenty-three papers were identified as meeting the selection criteria. Only one of the studies in this review reported a proxy for health status, but none examined whether salaried doctors differentiated between patients on the basis of health needs. Therefore, we were unable to draw conclusions on the likely impact of salaried payment on efficiency and equity. However, the limited evidence in our review does suggest that payment by salaries is associated with the lowest use of tests, and referrals compared with FFS and capitation. Salary payment is also associated with lower numbers of procedures per patient, lower throughput of patients per doctor, longer consultations, more preventive care and different patterns of consultation compared with FFS payment.
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Abstract
Recent guidelines published by the National Osteoporosis Foundation (NOF) make extensive use of quality-adjusted life-years (QALYs). Crucial to these guidelines, therefore, are the assumptions that are made about the health-related quality of life (HRQoL) gained from the avoidance of osteoporotic fractures. This paper reports on a study in which 50 Colles' fracture patients were asked to describe their health at each visit during treatment using the EuroQol descriptive system and to value their own health using the visual analogue scale (VAS). By applying a set of population-derived valuations to the states reported by the patients, the QALY loss is shown to be about 2%. This is about half of the loss, based upon clinician judgement, that is contained in the NOF guidelines. In addition, the results suggest that it may be possible to use VAS scores to predict treatment requirements, since those patients who require fewer visits have, on average, higher initial VAS scores.
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Roberts C, Torgerson D. Randomisation methods in controlled trials. BMJ (CLINICAL RESEARCH ED.) 1998; 317:1301. [PMID: 9804722 PMCID: PMC1114206 DOI: 10.1136/bmj.317.7168.1301] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Roland M, Torgerson D. Understanding controlled trials: what outcomes should be measured? BMJ (CLINICAL RESEARCH ED.) 1998; 317:1075. [PMID: 9774302 PMCID: PMC1114071 DOI: 10.1136/bmj.317.7165.1075] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Torgerson D, Giuffrida A. Patient compliance. Paid to comply. THE HEALTH SERVICE JOURNAL 1997; 107:30. [PMID: 10174020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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Campbell M, Torgerson D. Confidence intervals for cost-effectiveness ratios: the use of 'bootstrapping'. J Health Serv Res Policy 1997; 2:253-5. [PMID: 10182254 DOI: 10.1177/135581969700200410] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Torgerson D, Campbell M. Unequal randomisation can improve the economic efficiency of clinical trials. J Health Serv Res Policy 1997; 2:81-5. [PMID: 10180369 DOI: 10.1177/135581969700200205] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVES In the majority of clinical trials patients are randomised equally between treatment groups. This approach maximises statistical power for a given total sample size. The objectives of this paper were to determine if, when research costs between treatments differ, it is more economically efficient to randomise additional patients to the cheaper treatment, and how the optimum randomisation ratio can be estimated. METHODS Estimation of the most economically efficient randomisation ratio for four hypothetical clinical trials using cost-effectiveness analysis. RESULTS When research costs differ between treatments, and there is no constraint on total sample size, it is always more cost-effective to randomise more patients to the cheaper treatment. For example, a cost ratio between the lesser and more expensive treatment of ten, results in a randomisation ratio of 3.2:1. CONCLUSIONS Unequal randomisation ratios should be more widely used as this will achieve optimum statistical power for the lowest expenditure of research resources.
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