Trappenburg 2011.

Methods	Study design: parallel‐group randomised controlled trial Location, number of centres: Netherlands, University Medical Centre Ultrecht. Participants were recruited from 7 regional hospitals and 5 general practices in the Netherlands. Duration of study: 6 months
Participants	N screened: 391 N randomised: 233 (AP 111, UC 122) N completed: AP 91 completed 6 months, 21 dropped out (11 withdrew consent, 2 died, 5 comorbidity, 2 moved/logistics, 1 invalid); UC 102 completed 6 months, 20 dropped out (15 withdrew consent, 2 died, 2 comorbidity, 1 invalid) Baseline characteristics: mean age, years (SD) AP 66.1 (11.2), UC 65.1 (10.0); male, n (%) AP 65 (59), UC 69 (57); mean FEV1, % predicted (SD) AP 56.7 (20.3), UC 56.5 (20.6); current smoker, n (%) AP 31 (28), UC 37 (30); hospitalised for COPD in past year, n (%) AP 22 (20), UC 21 (18); number in group AP 111, UC 122; BMI (SD) AP 26.1 (5.5), UC 26.7 (6.5); living alone, n (%) AP 27 (23), UC 22 (18); education: lower secondary or less, n (%) AP 69 (62), UC 83 (68); higher secondary, n (%) AP 29 (26), UC 31 (25); college/university, n (%) AP 13 (12), UC 8 (7); GOLD stage: I, n (%) AP 14 (13), UC 13 (11); II, n (%) AP 55 (50), UC 58 (47); III, n (%) AP 30 (27), UC 38 (31); IV, n (%) AP 11 (10), UC 12 (10); FEV1, mean (SD) AP 1.55 (0.60), UC 1.59 (0.71); FVC, mean (SD) AP 3.03 (0.79), UC 3.17 (0.91); recruited from: GP, n (%) AP 18 (16), UC 17 (14); outpatient clinic, n (%) AP 93 (84), UC 105 (86) Inclusion criteria: postbronchodilator ratio of forced expiratory volume in 1 second to forced vital capacity (FEV1/FVC) < 70%. Age > 40 years. Smoking history > 20 years or 15 pack‐years. Diagnosis of COPD as a major functionally limiting disease. Current use of bronchodilator therapy Exclusion criteria: primary diagnosis of asthma. Primary diagnosis of cardiac disease. Presence of disease that could affect mortality or participation in the study (e.g. confusional states)
Interventions	AP group: At inclusion, participants were seen by the nurse case manager (respiratory nurse), who systematically checked and discussed; aspects of COPD care: vaccination, optimisation of medication, inhalation techniques, exercise, nutritional aspects, smoking (cessation) and exacerbation management. Participants in the AP group were encouraged to contact their case manager if they needed further information or wanted to ask a question. Two standardised reinforcement sessions were held by telephone at 1 and 4 months to evaluate participant understanding of and adherence to AP and, when needed, additional information was provided. An action plan for participants was individualised by a respiratory nurse and included: (1) a list of important contact persons and telephone numbers; resource persons: family physician, respiratory physician and respiratory nurse; (2) stable symptom severity (individual stable/normal green zone symptom status); (3) regular medication/lifestyle prescriptions (green zone); (4) additional medication/breathing exercises and energy preservation in case of symptom increase (yellow zone, orange zone); (5) a name contact person/telephone number in case of an exacerbation (orange zone). For individual participants, it was optional for the case manager (in consultation with the attending physician) to provide self‐treatment medication (course of corticosteroids and/or antibiotics). Participants also received usual care, which included pharmacological and non‐pharmacological care according to the most recent evidence‐based guidelines. UC group: At inclusion, participants were seen by a nurse case manager (respiratory nurse), who systematically checked and discussed aspects of COPD care: vaccination, optimisation of medication, inhalation techniques, exercise, nutritional aspects, smoking (cessation) and exacerbation management. No additional contacts with nurse educator. Participants in control group did not receive additional telephone sessions. Participants did not receive an action plan. Received usual care including pharmacological and non‐pharmacological care according to the most recent evidence‐based guidelines Follow‐up time points: assessments at baseline and at 6 months. All participants were contacted by telephone monthly; participants in the AP group received additional telephone follow‐up at 1 and 4 months to evaluate understanding and adherence to the action plan.
Outcomes	Primary outcome: time to recovery of health status in the event of an exacerbation All outcomes • Number of exacerbations • Time to recovery from exacerbation • Exacerbation rates • Anthonisen classification of COPD exacerbations • Percentage of exacerbations reported to a healthcare provider • Number respiratory‐related hospital admissions • Hospital days • Emergency room visits • Scheduled visits • Unscheduled visits • Telephone calls to respiratory or family physicians • Symptom diary • Health‐related quality of life • Anxiety and depression • Self‐management exacerbation‐related self‐efficacy*
Notes	Funding: not declared in protocol/trial registration or in results publication *Exacerbation‐related self‐efficacy measured by study‐developed questionnaire, consisting of 11 items for which confidence in self‐management capability in the occurrence of an exacerbation is graded on a 5‐point Likert scale. Lower scores indicate high confidence in adequate exacerbation‐related self‐management behaviour. No validity or responsiveness data published for this questionnaire
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Randomisation was carried out using the minimisation technique to balance the control and intervention groups for centre and gender." Probably done, as earlier reports from the same study authors clearly describe randomisation stratified by centre and gender
Allocation concealment (selection bias)	Low risk	"To conceal the assignment sequence, a central web‐based service was used." Probably done, as earlier reports from the same investigators clearly describe use of a central web‐based service for allocation concealment
Blinding (performance bias and detection bias) Participants	Low risk	"The modified informed consent procedure (postponed information) meant that patients were unaware of the major aim of the study." Probably done. Postponing receipt of information from participants allowed for adequate blinding of participants. Risk of cross‐contamination between members of intervention and control groups was reduced by stratification of randomisation by centre
Blinding (performance bias and detection bias) Study personnel	Low risk	Health professionals would have been aware of which participants were receiving the intervention. This is unlikely to be a significant source of bias.
Blinding of outcome assessment (detection bias) Objective outcomes, e.g. healthcare utilisation	Low risk	"All patients were contacted for monthly evaluation by telephone to assess healthcare utilisation and to evaluate proper use of the diary (figure 1)" (healthcare utilisation). Assessors were not blinded, as participants may have disclosed whether or not they were receiving an action plan. "To ensure rigorous and complete exacerbation counts, all diaries were reviewed by three blinded investigators who adjudicated events by consensus" (exacerbations). Unclear from information in the diary whether assessors would have been aware if the participant was receiving an action plan
Blinding of outcome assessment (detection bias) Subjective outcomes eg quality of life, anxiety	Low risk	"All patients were instructed to record daily in a diary whether symptoms were increased over their baseline condition" (patient‐reported outcomes). Participants were unaware of the major aim of the study, hence self‐reported outcomes were unlikely to be biased.
Incomplete outcome data (attrition bias) Health care utilisation (objective)	Low risk	Drop‐outs 19% intervention and 16% control group. Reasons for withdrawals were given and were balanced in both groups.
Incomplete outcome data (attrition bias) Subjective e.g. Quality of life	Low risk	Drop‐outs 19% intervention and 16% control group. Reasons for withdrawals were given and were balanced in both groups.
Selective reporting (reporting bias)	Low risk	Medical Research Council Dyspnoea Scale (MRC scale) was reported as a secondary outcome in the protocol but is not listed in the report. All other outcomes listed in the protocol are reported.
Other bias	Low risk	No other issues of bias