Dihigo 1998.

Methods	Study design: randomised controlled trial of parental counselling to modify the parent‒infant interaction vs empathy and support only Location: USA Setting: recruitment occurred in paediatrician offices in Dallas/Fort Worth Metroplex
Participants	Sample size: 14 infants Number of dropouts/withdrawals: 0 infants Mean age: intervention group = 6.31 weeks (SD = 2.36), control group = 6.25 weeks (SD = 3.37) Inclusion criteria: less than 3 months of age normal history of growth and development normal physical examination no history of vomiting or diarrhoea experienced symptoms associated with colic as determined by the infant's paediatrician Exclusion criteria: none stated
Interventions	Intervention group (n = 8): received individualised parental counselling, flow charts, and handouts to teach the parent of the colicky infant how to respond quickly and appropriately to their infant's cues Control group (n = 6): received empathy and support from the researcher Duration of intervention: 6 days
Outcomes	Primary outcome: crying time. Data were collected in parental diaries. Intervention group: crying time at baseline = 3.79 hours per day; crying time at post‐test = 1.12 hours per day. P value < 0.05 Control group: crying time at baseline = 3.08 hours per day; crying time at post‐test = 3.25 hours per day. P value < 0.05 Secondary outcome: infant sleep, measured by qualitative data recorded in parental diaries. Parents in the intervention group suggested their infants were sleeping more than before.
Notes	Study start date: not stated Study end date: not stated Declared DOI: none stated Perceived DOI: none perceived Funding source: none stated Other comments: none
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: study states participants randomly assigned but method of randomisation not described
Allocation concealment (selection bias)	Unclear risk	Comment: method not described
Blinding of participants and personnel (performance bias) All outcomes	High risk	Comment: participants and researcher both aware of interventions received
Blinding of outcome assessment (detection bias) All outcomes	High risk	Comment: parents of infants recorded crying times in diaries and were aware of intervention received
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: no withdrawals or losses to follow‐up
Selective reporting (reporting bias)	Low risk	Comment: study appears free of selective reporting
Other bias	Low risk	Comment: none noted