Hebestreit 2010.

Study characteristics
Methods	Randomised controlled study (60% allocation to intervention group); 1‐year intervention period, 2‐year follow up. Multicentre (3 German CF centres).
Participants	38 paediatric and adult CF patients. Intervention group n = 23, Control group n = 15. Participants recruited in outpatient setting from 1 of 3 German CF centres (Hannover, Wurzburg, Frankfurt). Mean (SD) age: Intervention group 19.5 (6.4) years; Control group 19.4 (5.3) years. No significant difference between groups at baseline in terms of spirometry (FEV1 % predicted, Intervention group 69.1 (17.2); Control group 75.6 (21.9)), participant gender or age.
Interventions	Intervention Group Participants in the intervention group agreed to increase physical activity by a minimum 3 hours/week for the first 6 months of the study. Participants received in‐person counselling with an exercise specialist at baseline, 3 months and 6 months. An individualised exercise plan was devised for each participant in the intervention group based on exercise test outcome and clinical data, as well as patient preference for activity. Participants in the intervention group received fortnightly phone consults for the first 6 months of the study to check on activity behaviour and offer additional help if required. Control Group Participants in the control group were instructed to keep their physical activity level constant for the 1st 12 months of the study. During the 2nd year of the study, control participants were able to change their physical activity behaviour if they wished.
Outcomes	Outcomes assessed at 3, 6, 12, 18 and 24 months. Vigorous physical activity: hours/week ‐ self reported. Physical activity participation: hours/week ‐ Actigraph accelerometer count measured over 7 days (completed at 6‐month time‐point only). QOL: CFQ14+ ‐ German CF Questionnaire. Exercise capacity (VO2 peak): ml/kg/min ‐ highest VO2 achieved over 30 seconds during a continuous incremental cycle test. Work max: w/kg ‐ power maintained during 1‐minute of last stage completed of incremental exercise test. Muscle power: peak power (PP) and mean power (MP) determined via Wingate test. Lean body mass: kg. Skin fold thickness: mm ‐ sum of 4 measurements. Body fat %. Pulmonary function: FEV1 % predicted; FVC % predicted; RV/TLC % predicted.
Notes	Results presented for baseline, 3 ‐ 6 months, 12 months and 18 ‐ 24 months follow up.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Recuited participants drew a folded paper ticket indicating their group randomisation.
Allocation concealment (selection bias)	Low risk	Participant randomisation occurred by the drawing of a folded paper ticket from an opaque bag. The ticket was destroyed following removal.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Participants and personnel aware of group allocation, the nature of the intervention would make this type of blinding difficult.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Unknown if outcome assessments performed by blinded personnel. Activity participation via accelerometry and skin‐fold measures likely subjected to minimal assessment bias. Assessment of QOL and exercise capacity could be open to bias.
Incomplete outcome data (attrition bias) All outcomes	High risk	Fewer than 15% of assessed participants were excluded and withdrawals were described and time point indicated. At 24‐month follow‐up the dropout rate was 26%. Intention‐to‐treat analysis was not performed.
Selective reporting (reporting bias)	Unclear risk	Outcome measures reported as outlined. Data only presented for the QOL category where there was significant change. Only numerical data presented for spirometry parameter where a change was seen. Results of activity intensity (HR recording) was not presented due to compliance being too poor to gain valid data (communication from author).
Other bias	Unclear risk	Participants in the intervention group were offered logistic and financial support, if needed, to foster the realisation of the activity programme.