Evaluating non-randomised intervention studies - NIHR Health ...

© Queen’s Printer and Controller of HMSO 2003. All rights reserved.Review Method of incorporating Results of quality investigationquality into synthesisSmeenk, 1998 359 Qualitative Narrative summary of study results and their quality scores was provided. RCTs and NRS appeared todemonstrate similar effects. Effectiveness of the intervention remains unclear.Snowdon, 1997 400 Qualitative Quality issues discusses narratively. Authors conclude there is no evidence of benefit and that most of the studieswere methodologically flawedSolomon, 1997 366 Qualitative Quality issues discussed alongside results of each study. Some indication of differences between care providerswas found, but important methodological limitations remainedSullivan, 1995 290 Not consideredTalley, 1996 401 Qualitative The methodological quality of the studies was discussed in detail; only one study was deemed of acceptablequality; however, its results were not felt to be generalisableTangkanakul, 1997 372 QualitativeMethodological quality discussed separately from study results. Some indication of benefit for the interventionwas found, but too few RCTs and too many problems with NRS to make strong recommendationster Riet, 1990 68 Qualitative Methodological issues were discussed and study results (positive or negative) were examined in relation to thequality of the studies. The authors conclude that no high-quality studies exist and no definitive conclusions cantherefore be reached regarding efficacy.Theis, 1997 373 Qualitative Some quality issues discussed. Methodological problems mean that available studies provide only very limitedcomparative data on the benefits of different treatment protocolsThomas, 1995 375 Qualitative Comment was made on poor methodological quality of included studies, making definitive conclusions impossibleTowler, 1998 235 Qualitative Design issues discussed narratively. Quality of design generally high. Studies examined according to designvan Balkom, 1997 384 QuantitativeMagnitude of effect size was not significantly associated with quality score.Correlation between quality score and effect Multivariate analysis indicated that eight independent variables including quality score and confounding variablessize accounted for 15% of the variance for panic (F = 0.9; df = 8,42; p = 0.53), and 21% for agoraphobia (F = 2.81;Multiple regression analysis using eight df = 8,87; p = 0.008). In the Discussion section, the authors further state that total quality score was onlyvariables: % of drop-outs, male/female weakly correlated with outcomeratio, duration of illness, age at onset, ageat start of trial, type of diagnosis, % ofpatients with panic disorder alone and thetotal quality scoreVerhagen, 1997 304 Qualitative The methodological quality and results of the studies were discussed separately. Authors conclude that aconclusion regarding efficacy cannot be drawn owing to poor methodological qualityVickers, 1996 201 Qualitative Methodological quality of the studies was discussed in some detail. The authors conclude that the intervention iseffective but acknowledge that methodological flaws may lead some readers to conclude that there is insufficientevidencecontinuedHealth Technology Assessment 2003; Vol. 7: No. 27165