Table 1. Detailed description of risk of bias assessment using Newcastle-Ottawa Scale (NOS).

Domains		Predefined criteria	Maximum number of stars per domain
Selection	Representativeness of exposed cohort (children with CP and visual impairment)	* Cohort truly representative of the average child with a primary CP aged 0–18 or 0–21 years in the community together with a description of key characteristics (age, gender, tumour type etc.)     • Selected group of children with CP (e.g. only giant CP)     • No description of key characteristics	****
	Selection of non-exposed cohort (children with CP without visual impairment)	* Cohort drawn from the same community as the exposed cohort     • Cohort drawn from a different source     • No description of the derivation of the non-exposed cohort
	Ascertainment of exposure (CP)	* Medical records / histological confirmation     • No description
	Demonstration that outcome of interest (visual impairment) was not necessarily present at start of study	* Outcome of interest was not an inclusion criterion for study     • Outcome of interest was an inclusion criterion for study
Comparability	Comparability of cohorts on the basis of the design of analysis	NA or for studies with > 1 cohort: * Only children (aged 0–21 years) included in both cohorts * Tumour locations were reported in both cohorts	NA or **
Outcome	Assessment of outcome	* VA and VF were reported     • Only global information about visual function at diagnosis	*
	Was follow-up long enough for outcomes to occur	NA
	Adequacy of follow-up of cohorts	NA

CP: Craniopharyngioma. NA: Not applicable. Items do not apply to the research question and design of this review.