Paul Knipschild

The Delphi list: a criteria list for quality assessment of randomized clinical trials for conducting systematic reviews developed by Delphi consensus.

Most systematic reviews rely substantially on the assessment of the methodological quality of the individual trials. The aim of this study was to obtain consensus among experts about a set of generic core items for quality assessment of randomized clinical trials (RCTs). The invited participants were experts in the field of quality assessment of RCTs. The initial item pool contained all items from existing criteria lists. Subsequently, we reduced the number of items by using the Delphi consensus technique. Each Delphi round comprised a questionnaire, an analysis, and a feedback report. The feedback report included staff team decisions made on the basis of the analysis and their justification. A total of 33 international experts agreed to participate, of whom 21 completed all questionnaires. The initial item pool of 206 items was reduced to 9 items in three Delphi rounds. The final criteria list (the Delphi list) was satisfactory to all participants. It is a starting point on the way to a minimum reference standard for RCTs on many different research topics. This list is not intended to replace, but rather to be used alongside, existing criteria lists.

Clinical trials of homoeopathy.

OBJECTIVE--To establish whether there is evidence of the efficacy of homoeopathy from controlled trials in humans. DESIGN--Criteria based meta-analysis. Assessment of the methodological quality of 107 controlled trials in 96 published reports found after an extensive search. Trials were scored using a list of predefined criteria of good methodology, and the outcome of the trials was interpreted in relation to their quality. SETTING--Controlled trials published world wide. MAIN OUTCOME MEASURES--Results of the trials with the best methodological quality. Trials of classical homoeopathy and several modern varieties were considered separately. RESULTS--In 14 trials some form of classical homoeopathy was tested and in 58 trials the same single homoeopathic treatment was given to patients with comparable conventional diagnosis. Combinations of several homoeopathic treatments were tested in 26 trials; isopathy was tested in nine trials. Most trials seemed to be of very low quality, but there were many exceptions. The results showed a positive trend regardless of the quality of the trial or the variety of homeopathy used. Overall, of the 105 trials with interpretable results, 81 trials indicated positive results whereas in 24 trials no positive effects of homoeopathy were found. The results of the review may be complicated by publication bias, especially in such a controversial subject as homoeopathy. CONCLUSIONS--At the moment the evidence of clinical trials is positive but not sufficient to draw definitive conclusions because most trials are of low methodological quality and because of the unknown role of publication bias. This indicates that there is a legitimate case for further evaluation of homoeopathy, but only by means of well performed trials.

Carpal tunnel syndrome prevalence in the general population

To study the prevalence of carpal tunnel syndrome (CTS) in the general population and the value of brachialgia paraesthetica nocturna (BPN) in diagnosing CTS, an age and sex stratified random sample of 715 subjects was taken from the population register of Maastricht (The Netherlands) and surrounding villages, between September 1983 and July 1985. The response rate was 70%. Of these, 12 CTS cases had already been diagnosed. Of the remaining subjects, 64 (13 men, 51 women) woke up because of BPN. Among these subjects 1 man and 23 women were found to have CTS. The prevalence rate of undetected CTS was 5.8% [95% confidence interval (CI): 3.5-8.1%] in adult women; 3.4 percent (95% CI: 1.5-5.3%) had already been diagnosed as CTS. The overall prevalence rate for men was 0.6% (95% CI 0.02-3.4%). These figures have to be regarded as minimal estimates. The overall diagnostic value of BPN for CTS was 38%, while for women only this was 45% (95% CI: 31-60%).

Acupuncture and chronic pain: A criteria-based meta-analysis

A literature search revealed 51 controlled clinical studies on the effectiveness of acupuncture in chronic pain. These studies were reviewed using a list of 18 predefined methodological criteria. A maximum of 100 points for study design could be earned in four main categories: (a) comparability of prognosis, (b) adequate intervention, (c) adequate effect measurement and (d) data presentation. The quality of even the better studies proved to be mediocre. No study earned more than 62% of the maximum score. The results from the better studies (greater than or equal to 50% of the maximum score) are highly contradictory. The efficacy of acupuncture in the treatment of chronic pain remains doubtful.

Measuring the functional status of patients with low back pain. Assessment of the quality of four disease-specific questionnaires.

Study Design. This study was a literature review of the quality of four disease-specific functional status questionnaires for patients with low back pain: Oswestry; Million; Roland; and Waddell disability questionnaire. Objectives. The questionnaires were evaluated in terms of general description, scale structure, reliability, validity, responsiveness, and clinical research applications. Summary of Background Data. Functional status is an outcome of great interest for clinical trials of low back pain. Methods. A computer-aided search was conducted of articles published between 1981 and 1993 and references given in selected relevant publications. Articles were selected if at least one of the four functional status questionnaires was used or if the authors gave relevant information about the methodology of these questionnaires. Results. There was not enough information available about the criteria of item selection used for the development of the questionnaires. The test-retest reproducibility of the questionnaires seemed satisfactory. The Oswestry and Roland disability questionnaires have been used and evaluated more frequently than the Million and Waddell. Therefore, we can be more certain about the validity and responsiveness of the former pair of questionnaires. Conclusion. In the absence of a gold standard, direct comparisons of evaluative functional status questionnaires in a single patient group are needed. Through direct comparisons, comparative validity and responsiveness can be assessed. Functional status measures are not currently used in many settings in which they would be valuable. It is important to encourage their wider use in clinical trials. Additional research is needed to compare and improve the existing questionnaires.

Spinal manipulation and mobilisation for back and neck pain: a blinded review.

OBJECTIVE--To assess the efficacy of spinal manipulation for patients with back or neck pain. DESIGN--Computer aided search for published papers and blinded assessment of the methods of the studies. SUBJECTS--35 randomised clinical trials comparing spinal manipulation with other treatments. MAIN OUTCOME MEASURES--Score for quality of methods (based on four main categories: study population, interventions, measurement of effect, and data presentation and analysis) and main conclusion of author(s) with regard to spinal manipulation. RESULTS--No trial scored 60 or more points (maximum score 100) suggesting that most were of poor quality. Eighteen studies (51%) showed favourable results for manipulation. In addition, five studies (14%) reported positive results in one or more subgroups. Of the four studies with 50-60 points, one reported that manipulation was better, two reported that manipulation was better in only a subgroup, and one reported that manipulation was no better or worse than reference treatment. Eight trials attempted to compare manipulation with some placebo, with inconsistent results. CONCLUSIONS--Although some results are promising, the efficacy of manipulation has not been convincingly shown. Further trials are needed, but much more attention should be paid to the methods of study.

The effectiveness of manual therapy, physiotherapy, and treatment by the general practitioner for nonspecific back and neck complaints : a randomized clinical trial

In a randomized trial, the effectiveness of manual therapy, physiotherapy, continued treatment by the general practitioner, and placebo therapy (detuned ultrasound and detuned short-wave diathermy) were compared for patients (n = 256) with nonspecific back and neck complaints lasting for at least 6 weeks. The principle outcome measures were severity of the main complaint, global perceived effect, pain, and functional status. These are presented for 3, 6, and 12 weeks follow-up. Both physiotherapy and manual therapy decreased the severity of complaints more and had a higher global perceived effect compared to continued treatment by the general practitioner. Differences in effectiveness between physiotherapy and manual therapy could not be shown. A substantial part of the effect of manual therapy and physiotherapy appeared to be due to nonspecific (placebo) effects.

Physiotherapy exercises and back pain: a blinded review.

OBJECTIVE--To determine the quality of randomised controlled trials of exercise therapy for back pain. DESIGN--Computer aided search of published papers and blinded assessment of the methods of studies. SUBJECTS--23 randomised controlled trials, of which 16 studied exercise therapy given by physiotherapists to individual patients with back pain. Other conservative treatments could be included. MAIN OUTCOME MEASURES--Score for quality of methods (based on four main categories: study population, interventions, measurement of effect, and data presentation and analysis) and main conclusion of author(s) with regard to exercise therapy. RESULTS--Only four studies scored more than 50 points (maximum 100), indicating that most were of poor quality. Six studies found that exercise was better than reference treatments and 10 reported it to be no better or worse than the reference treatment. Those reporting positive results tended to have higher methods scores (4/6 positive v 4/10 negative scored greater than or equal to 42). CONCLUSIONS--No conclusion can be drawn about whether exercise therapy is better than other conservative treatments for back pain or whether a specific type of exercise is more effective. Further trials are needed in which greater attention is paid to methods of study.

Efficacy of provocative tests for diagnosis of carpal tunnel syndrome

The validity of twelve provocative tests for carpal tunnel syndrome (CTS) in a random sample of 504 people from the general population was assessed. 50 woke up at night due to paraesthesiae (with or without numbness or pain) in the fingers innervated by the median nerve (CTS symptoms) in 93 hands. CTS was neurophysiologically confirmed in 28 subjects (44 hands)--a prior probability for CTS of 47%. All clinical diagnostic tests had a low validity. Posterior probability of CTS ranged from 35 to 70% for positive test results and from 41 to 62% for negative test results. A combination of three tests with relatively high validity (paresis of abductor pollicis brevis muscle, hyperpathia, and flick sign) did not significantly change the probability of CTS. Patients with CTS symptoms should be referred directly for neurophysiological examination.

The efficacy of ginkgo for elderly people with dementia and age-associated memory impairment: new results of a randomized clinical trial.

OBJECTIVES: To evaluate the efficacy, the dose‐dependence, and the durability of the effect of the ginkgo biloba special extract EGb 761 (ginkgo) in older people with dementia or age‐associated memory impairment.