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. 2022 Aug 9;2022(8):CD002768. doi: 10.1002/14651858.CD002768.pub5

Klijn 2004.

Study characteristics
Methods Design: single‐centre, parallel RCT
Location: Cystic Fibrosis Center at University Medical Center, Utrecht, Netherlands
Inclusion criteria: participants with CF aged 9–18 years; stable clinical condition (i.e. no need for oral or IV antibiotic treatment in the 3 months prior to testing); absence of musculoskeletal disorders; and FEV1 > 30% predicted
Exclusion criteria: not specified
Duration: 12 weeks
Participants 20 participants with CF (stable disease) completed study
Group demographics
Intervention group: (n = 11): mean age 13.6 (SD 1.3) years
Control group: (n = 9): mean age 14.2 (SD 2.1) years
3 participants dropped out: 1 withdrew from the training group for practical reasons, and 2 from the control group as they did not complete assessments due to pulmonary exacerbations.
Interventions Long‐term anaerobic study (12 weeks)
Intervention group: anaerobic exercise (2 days per week for 30–45 min)
Control group: normal daily activities
Outcomes

  1. Change in anaerobic performance measured by Wingate Anerobic Test (PP, MP)

  2. Change in body composition (BMI, fat‐free mass)

  3. Change in lung function (FEV1; FVC; FEF25–75; RV/TLC)

  4. Change in aerobic capacity (VO2 peak; peak working capacity; VCO2; VE; RER; lactate)

  5. Change in HAES

  6. Change in HRQoL (CFQ)


Outcomes were measured at baseline and after 12 weeks.
Notes To achieve a difference in PP per kg BW of 10% with an SD of 0.8 W/kg and a statistical power of 80%, it was calculated that 8 participants had to be included in each study group.
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Unclear risk Described as randomised, but no details of the method.
Allocation concealment (selection bias) Low risk Allocation concealed in opaque envelopes.
Blinding of participants and personnel (performance bias)
All outcomes High risk Not possible to blind participants to intervention. Primary researcher was blinded but their role in the study was unclear.
Blinding of outcome assessment (detection bias)
All outcomes Unclear risk Primary researcher was blinded, but it was unclear whether this researcher was responsible for outcome assessment.
Incomplete outcome data (attrition bias)
All outcomes Low risk Clear description and details about dropouts. 3 participants dropped out: 1 participant from the training group withdrew for practical reasons; 2 from the control group did not complete assessments due to pulmonary exacerbations.
Intention‐to‐treat analysis was not performed.
Selective reporting (reporting bias) Unclear risk Results for HRQoL are only presented for the scale 'physical functioning', which was significantly higher in the training group after the 12‐week training period. There were no change in this HRQoL scale in the control group after 12 weeks. There were no significant effects for any other HRQoL scales. Data were not reported in detail.
Other bias Unclear risk Clearly stated inclusion criteria but exclusion criteria were not reported. Described statistical methods used in analysis.