Alfuzosin

CONSORT guidelines should be expanded

EDITOR--Sanders et al's bibliographic study on the frequency and detail of reporting on quality of life data in randomised controlled trials listed in the Cochrane Controlled Trials Register is disturbing.[1] Despite increasing emphasis on patient centred outcomes in all aspects of clinical practice and research, less than 5% of trials reported on quality of life and even fewer comprehensively reported the quality of data using well validated, familiar instruments.

Deyo and Patrick discussed methodological, attitudinal, and conceptual barriers to the use of quality of life assessments in research in 1989.[2] They noted the paucity of information regarding the responsiveness, reliability, validity, and psychometric characteristics of most instruments. In the 1980s many authors noted the problem of a confusing array of instruments, including scales with the same purpose.[2 3] Feinstein et al noted 43 scales measuring activities of daily living.[3]

Deyo and Patrick suggested increased reporting of studies that compared different quality of life instruments in the same population and comparing the use of generic instruments in different diagnostic groups. They also advocated testing any newly developed instruments against well established scales and the development of a "quality of life research laboratory" to aid researchers with the analysis and standardisation of data on quality of life.[2]

In the light of Sanders et al's study, all trialists need to think again about the suggestions above. The CONSORT guidelines could be expanded to include recommendations on which tested, well validated quality of life instruments should be selected for use in different situations. This would aid researchers' choice and improve standardisation and generalisability.

[1] Sanders C, Egger M, Donovan J, Tallon D, Frankel S. Reporting on quality of life in randomised controlled trials: bibliographic study. BMJ 1998;317:1191-4. (31 October.)

[2] Deyo R, Patrick D. Barriers to the use of health status measures in clinical investigation, patient care and policy research. Med Care 1989;27:S254-68.

[3] Feinstein AR, Josephy BR, Wells CK. Scientific and clinical problems in indexes of functional disability. Ann Intern Med 1986;105:413.

Susan P Wright Cardiovawular research fellow

Department of Medicine University of Auckland, Auckland, New Zealand sp.wright@auckland.ac.nz

Authors are creating database of quality of life questionnaires

EDITOR--Sanders et al reported that the presentation of quality of life data in clinical trials was often flawed.[1] We are creating a database of quality of life questionnaires used in clinical trials and are assessing the quality of the trials with a checklist that we have drawn up. We have encountered 10 main biases:

(1) The trial is not comparative.[2]

(2) No justification is given of the number of patients included--the number may be too small to achieve enough power to detect a difference between two treatments or too large, leading to a difference that is significant but not clinically relevant.[3]

(3) The quality of life questionnaire is not validated, and its responsiveness has not been tested.

(4) No description is provided of the follow up of patients during the study.

(5) No description is given of withdrawals and the handling of missing data.

(6) Analysis of quality of life data is performed on a per protocol basis instead of on an intention to treat basis--for example, [is less than] 530 patients are analysed instead of the 812 randomised in a trial comparing ranitidine with placebo in gastro-oesophageal reflux.[3]

(7) The presentation of quality of life results is flawed--for example, only graphs are presented and no actual value is given, and standard deviations of scores in the different domains of quality of life are missing.

(8) Ideally, the confidence intervals of the differences between treatment groups or the size effect, or both, should be given.

(9) The level of significance is not adapted to the number of statistical comparisons, leading to an increased a error.

(10) The clinical relevance of the results relating to quality of life is not discussed--for example, when only two or three among eight or nine domains of the quality of life questionnaire improve significantly in one group compared with the other[3 4] or when the differences in quality of life scores between groups seem slight.[3] In Liard et al's study, in which a specific questionnaire was used as a primary end point, only two of the nine domains had improved significantly with naftidrofuryl at six months. These two domains were pain and daily life, the minimum goals for a treatment claiming to alleviate symptoms of arteriopathy.[4]

Assessment of quality of life requires rigorous methodology, follow up of patients, and statistical analysis. Thus reporting on quality of life should be considerably improved and should follow the CONSORT guidelines.

[1] Sanders C, Egger M, Donovan J, Tallon D, Frankel S. Reporting on quality of life in randomised controlled trials: bibliographic study. BMJ 1998;317:1191-4. (31 October.)

[2] Lukacs B, McCarthy C, Grange JC, QOL BPH Study Group in General Practice. Long-term quality of life in patients with benign prostatic hypertrophy: preliminary results of a cohort survey of 7093 patients treated with an alpha-l-adrenergic blocker, alfuzosin. Eur Urol 1993; 24(suppl 1):34-40.

[3] Rush DR, Stelmach WJ, Young TL, Kirchdoerfer LJ, Scott-Lennox J, Holverson HE, et al. Clinical effectiveness and quality of life with ranitidine vs placebo in gastroesophageal reflux disease patients: a clinical experience network (CEN) study..] Fam Pract 1995;41:126-36.

[4] Liard F, Benichou AC, Gamand S, Lehert P. The effects of naftidrofuryl on quality of life. Dis Manage Health Outcomes 1997;2(suppl 1):71-8.

Olivier Chassany Senior lecturer in therapeutics

Jean Francois Bergmann Professor of therapeutics

Charles Caulin Professor of therapeutics

Service de Medecine Interne, Hospital Lariboisiere, 75010 Paris, France olivier.chassany@lrb.ap-hop-paris.fr

Competing interests: None declared.

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