Poustie 2006.

Methods	Randomised controlled study. Duration: 12 months. Parallel design. Multicentre (7 specialist paediatric CF centres and their associated shared care clinics and 7 smaller paediatric CF clinics). Location: UK.
Participants	102 children aged 2 ‐ 15 years with CF and at least one of following criteria: BMI < 25th centile but > 0.4th centile; or no increase in weight over the previous 3 months; or 5% decrease in weight from baseline over a period of < 6 months. Treatment group (n = 50). Age (mean (SD)): 8.75 (3.72) years. Gender split: 27 males, 23 females. BMI centile (mean (SD)):34.27 (23.96). Weight centile (mean (SD)): 25.07 (20.37). Height centile (mean (SD)):26.69 (24.83). Energy intake (% EAR) (mean (SD)): 118.43 (28.71). FEV1 (% predicted) (mean (SD)): 81.34 (16.16). Control group (n = 52). Age (mean (SD)): 8.79 (3.67) years. Gender split: 27 males, 25 females. BMI centile (mean (SD)): 31.52 (25.36). Weight centile (mean (SD)): 24.69 (22.79). Height centile (mean (SD)): 28.15 (26.93). Energy intake (% EAR) (mean (SD)): 116.24 (29.59). FEV1 (% predicted) (mean (SD)): 73.67 (18.58).
Interventions	Treatment: oral calorie supplements (chosen by the children) in the form of drinks sufficient to increase usual energy intake by 20% plus routine dietetic advice. Control: dietary advice alone.
Outcomes	Change in BMI* Change in BMI percentile and z score* Change in weight* Change in height* Change in weight percentile* Change in height percentile* Mid‐upper arm circumference* Tricep skinfold Mid‐arm muscle circumference Energy* and macro‐nutrient* intake FEV1 & FVC expressed as % predicted for age, sex and height* Gastrointestinal symptoms* Eating behaviour Activity levels Lipase intake
Notes	Sample size calculation undertaken: with a 5% significance level and 90% power, using a conservatively estimated SD for 1 year change in BMI centile of 15 points, authors needed 47 children in each arm or 94 in total. The children selected the supplements that they liked, and we recommended a daily amount sufficient to increase usual energy intake by 20%. Excluded supplements that provided only energy or protein alone.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Paper states that random number tables were used to generate the randomisation code.
Allocation concealment (selection bias)	Low risk	Sequentially numbered, opaque envelopes, administered by the pharmacy of the lead centre, were used for treatment group allocation.
Blinding (performance bias and detection bias) All outcomes	Low risk	The research assistant was not masked to allocation group, but a masked investigator used a computerised growth package for conversion of weight and height to BMI centile. The children in the trial were not masked, as no satisfactory placebo was available. This however did not influence outcomes due to objectivity of the measures.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Paper states that investigators made every effort to obtain full outcome data on all participants, but replaced any missing data with routinely collected data where appropriate. Full reasons given for any drop outs or missing data (unable to collect interim data on 2 children from the treatment group (owing to parental choice or illness) and 1 child from the standard care group (illness)).
Selective reporting (reporting bias)	High risk	Paper appears to address all the outcomes measured in the 'Results' section. The investigators of the study have confirmed that assessment of eating behaviour was planned and undertaken, however due to concerns of the validity and reliability of the tools used to assess this outcome in the three age groups of participants, the data were not reported. Lipase intake was also assessed within the dietary diaries however data were not reported on this outcome in the key publication as the diaries were only returned by approximately half of the study participants.

BMI: body mass index
 CF: cystic fibrosis
 EAR: estimated average requirement for age and sex
 EPA: eicosapentaenoic acid
 FEV1: forced expiratory volume in 1 second
 FVC: forced vital capacity
 SD: standard deviation
 WFH : weight for height
 *: outcomes included in review