Quality of guidelines for the laboratory management of diabetes mellitus

BACKGROUND: There is increasing concern about the quality and reliability of practice guidelines, especially in the field of laboratory medicine, as most recommendations are developed by clinical specialty societies, often without involving laboratory professionals. Little information is available on the methodological quality of guidelines for the use of laboratory investigations in the care of specific diseases. We describe a pilot assessment of the most well-known guidelines for the diagnosis and monitoring of diabetes mellitus (DM). METHODS: Practice guidelines on DM published in English between 1999 and 2005 April were identified by systematic searching in Medline and international guideline databases. Fifty four DM guidelines were retrieved, of which 29 met our inclusion criteria. The four most widely used international guidelines (WHO, ADA, NACB, NICE) were selected for a critical appraisal of their methodological quality. This was carried out by seven independent assessors using a validated checklist, the AGREE Instrument. Twenty three guideline attributes arranged in six independent domains were investigated and the mean scores of assessors for each attribute and the aggregated scores for each domain were calculated. Cronbach's alpha and interclass correlations were calculated to measure internal consistency and reliability within each domain. The four guidelines were compared using one-way ANOVA and ANOVA using repeated measurements. RESULTS: The selected four guidelines on DM have significant shortcomings in demonstrating and/or reporting multidisciplinary stakeholder involvement in the guideline development process, evidence-based methodology for formulating recommendations, applicability of statements, and disclosing any conflicts of interest or reporting editorial independence. CONCLUSIONS: Poor quality and lack of explicitness of recommendations in laboratory medicine call for methodological standards of guideline development and reporting, and for an international collaboration of guideline development activities, to increase the internal and external validity of recommendations in laboratory practice.