Dijkstra 2006.

Methods	Randomization procedure: Random allocation done by person outside research group and concealed from investigators. 13 hospitals were stratified on the number of beds and diabetes specialist nurses and randomly assigned to control group (usual care), professional‐directed group or patient‐centered group. Sequence generation was not given Informed consent obtained: Yes (ethics committee approved study) Protection against contamination: Inadequate. Although there was cluster randomization, Diabetes passport (main patient‐centered tool) was promoted in a patient magazine on diabetes Outcomes assessors blinded: Unclear. Primary outcome was determined by diabetes nurse specialists (through chart review) and patient questionnaire. No statement that any were blinded Intention to treat analysis: Not done Potential for unit of analysis error: Yes. Primary outcome (HbA1c) randomisation by practice, but analysis by patient without concern for unit of analysis error. The problem was acknowledged and addressed with a multilevel logistic regression performed stepwise to explain differences in adherence rates Comments on study quality: Multicenter cluster RCT, intracluster correlation coefficient was given. Stratified on the number of beds and diabetes specialist nurses
Participants	Profession: Medicine Specialty: Internal medicine physicians (some are part of multi‐professional teams with diabetes specialist nurses, dieticians, and podiatrists) Years experience: Mean years in practice 16.3years. Mean age 47.8 years Clinical setting: Outpatient departments (general and special diabetes clinics) of consenting hospitals. University hospital and hospitals with ongoing intervention studies were excluded Level of care: Primary/secondary Country: The Netherlands Health problem/Type of patient: Type and 2 Diabetes mellitus patients who were visiting their physician for a diabetes check‐up. 47% male, mean age 58 years, Mean HbA1c 7.8 (1.2). No info on education, income, or culture
Interventions	Aim of study (hypothesis): To investigate whether a comprehensive strategy involving both patients and professionals with the introduction of a patient centred tool (diabetes passport) as a key component, improves diabetes care Content of intervention: Intervention activities were addressed to both healthcare professionals and to patients in intervention group. Intervention for professionals included first feedback on aggregated patient data, then educational session in which national diabetes opinion leader introduced guidelines on prevention and treatment of diabetes complications as well as diabetes passports and discussed barriers and facilitating factors to implementing the diabetes passports in the clinics. 6 months later, given feedback on clinical performance as well as on the use of the diabetes passport (info collected from patients). Intervention for patients included educational meetings organized in collaboration with the local patient organisations +Diabetes passports (introduced by internists) and leaflets explaining how to use them. Control hospital patients and physicians received no training from researchers and were told to continue usual care. However, national diabetes guidelines were sent to all Dutch hospitals and summary was published in leading Dutch medical journal during the study period. Furthermore, diabetes passport was promoted in patient magazine on diabetes Conceptual Focus: Sharing management of health problem with patient: Passport was developed with patient organization and based on guidelines that aim to educate and record results of medical examinations in order to promote shared disease management; no replicable skills were given (1/7) Duration and timing: data not given Number of providers receiving intervention: 39 Course + feedback (group A), 41 course only (group B), 41 feedback only (group C), 39 control (group D). Hospitals: G1 = 4, G2 = 4, control = 5 (start & end) Number of patient receiving intervention: 150 patients per internist. 1415 patients approached, 1350 given questionnaire. 600 patient in intervention (4 hospitals), 750 in control (5 hospitals). For analysis, n (Intervention) = 351 (58.5%); n (control) = 418 (55.7%); G1 = 248, G2 = 240, control = 276 (start) 77% end Fidelity/integrity of intervention: No data
Outcomes	Primary outcomes: HbA1c mean pre‐post Consultation process: Diabetes‐specific process measures at index visit and 12 months from medical record. Satisfaction: NA Health behaviours: NA Health status: HbA1c level (also systolic blood pressure, diastolic blood pressure, cholesterol, creatinine; from medical chart review by local diabetes specialist nurses)
Notes	References included in review of this article: 1) Dijkstra RF et al. Diabetic Medicine 2004;21:586‐591. 2) Dijkstra RF et al. 2005;23:164‐70 Meta‐analysis 1) Health Status, Continuous Unadjusted sample sizes: intervention: 351 patients /4 hospitals control: 418 patients /5 hospitals ICC: estimate per article: .01 DEFF: 1+ICCx[(intervention+control/cluster size)‐1] DEFF: 1+.01x[(351+418(/(4+5)‐1]=1.844 Adjusted sample sizes: intervention: 351/1.844 = 190; control: 418/1.844 = 227
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	13 hospitals were stratified on the number of beds and diabetes specialist nurses and randomly assigned to control group (usual care), professional‐directed group or patient‐centered group. Did not indicate how sequence was generated, but likely adequate given that it was done outside research group and concealed
Allocation concealment (selection bias)	Low risk	Random allocation done by person outside research group and concealed from investigators
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Primary outcome was determined by diabetes nurse specialists (through chart review) and patient questionnaire. No statement that any were blinded
Incomplete outcome data (attrition bias) All outcomes	High risk	Of 1415 patients approached, 1350 were given questionnaire. 600 were allocated to intervention, 750 were allocated to control. Pre‐intervention data was available in 458 (76.3%) intervention and 539 (71.9%) control. Only 351 (58.5%) of intervention and 418 (55.7%) control were analysed. Did not use intention to treat analysis
Selective reporting (reporting bias)	Low risk	primary outcome measure was mean HbA1c level drop of 0.5. Secondary outcomes were processes and other outcomes of diabetes. Authors did report results on all variables described in methods
Other bias	High risk	Protection against contamination was inadequate. Although there was cluster randomisation, Diabetes passport (main patient‐centered tool) was promoted in a patient magazine on diabetes. However, this would underestimate effects of intervention and study found positive result Potential for unit of analysis error was acknowledged and addressed with a multilevel logistic regression performed stepwise to explain differences in adherence rates. Baseline data were collected and addressed