An updated meta-analysis to assess the effectiveness of psychological interventions delivered by psychological specialists and generalist clinicians on glycaemic control and on psychological status

ObjectiveTo update a meta-analysis and determine the effectiveness of psychological interventions on glycaemic control measured by HbA1c and psychological status in type 2 diabetes and to compare effects when interventions are delivered by generalist clinicians compared to psychological specialists.MethodsWe used the original review protocol and searched the Cochrane central register of controlled trials, Medline, Embase, PsychLIT, and Google Scholar from February 2003 (end of previous review) to March 2007. We extracted data on the participants, interventions, delivery methods, comparison groups and outcome measures.Results35 trials were reviewed and meta-analysis of 19 trials (n = 1431), reporting HbA1c found a reduction in HbA1c by 0.54% (−0.32; 95% CI: −0.47 to −0.16). In nine trials (n = 832) interventions were delivered by diabetes or general clinicians reducing HbA1c by 0.51% (−0.27; 95% CI: −0.50 to 0.04). In nine trials, interventions (n = 561) were delivered by psychological specialists reducing HbA1c by 0.57% (−0.36; 95% CI: −0.61 to 0.12). Meta-analysis of 13 trials reporting psychological status found psychological status to be lower in the intervention groups −0.56 (95% CI: 1.00 to −0.13). Trial quality for the majority of studies remained poor.ConclusionOur findings suggest that psychological and general clinicians are similarly effective in delivering psychological interventions, however, effect sizes for all clinicians have reduced since the earlier review.Practice implicationsPsychological training opportunities for generalist clinicians could lead to wider availability of effective psychological care.