Markestad 1997.

Methods	Randomised, double‐blind, cross‐over trial
Participants	Sample size: 20 consecutive infants; 1 infant was excluded because of organic disease Setting: recruited from public healthcare clinics Sex: 13 boys, 6 girls Mean age: 7.3 (SD 3.4) weeks; range not reported Mean weight: 3502 (SD 570) grams Mean duration of colic: 5.2 (SD 3.0) weeks Mean crying: 5.7 (SD 2.6) hours Feeding: breast fed (17 purely breast fed, 2 partially breast fed) Birth order: not reported Inclusion criteria: Colic was defined as crying for a minimum of 3 hours per day 3 days a week for the past 3 weeks. Infants were between 3 weeks and 3 months old. Exclusion criteria: not specified
Interventions	Intervention (19 infants): sucrose, 12% solution in distilled water Placebo (19 infants): distilled water Administration: One bottle containing sucrose and 1 containing placebo were arranged in numbered pairs. Parents received oral and written instructions to give 2 mL of the distributed solution by syringe over 30 to 60 seconds, while holding the infant in their arms, when the infant continued to cry after attempts of consoling by feeding, by changing the nappy or by carrying had failed. Repeat visits were scheduled 3 to 4 and 6 to 8 days after the first visit, and a telephone interview was conducted 3 to 4 days after the last visit. On each visit, the bottle was returned, and the other of the pair was distributed. Duration of study: 8 days Washout period: no information
Outcomes	The infant was examined clinically at repeated visits, and on each contact (visit or telephone contact), the parent described the effect of the last treatment on a 5‐point scale: ‘getting worse’ to ‘no improvement’, ‘some improvement’, ‘marked improvement’, and ‘complete stop of crying after each dose’.
Notes	Country: Norway Funding source: Study authors did not report whether the study had received support.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: Study authors did not describe the randomisation method. Quote: "each infant was randomised to a number and which of the pair of bottles to be tried first by two separate draws using the sealed envelope technique".
Allocation concealment (selection bias)	Unclear risk	Comment: sealed envelope technique; not reported whether the envelopes were opaque.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Comment: Sucrose as a 12% solution in distilled water and placebo as distilled water were prepared by a pharmacist, who also arranged and kept the coding, and distributed treatment in identical coloured glass bottles.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Comment: Only the pharmacist knew which material the child had received.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: 19 infants completed the study and were analysed.
Selective reporting (reporting bias)	High risk	Comment: Study authors did not report results by study period.
Other bias	Unclear risk	Comment: No information about washout period was reported.