TABLE 1.

Quality of evidence scoring tool

		Score
Scoring domain		Strong	Moderate	Weak
Data source	Was the data source complete and representative of the population as a whole?	Community/population‐based screening/newborn screening Disease registry	Hospital‐based records Laboratory‐based records General practice‐based records	Survey by query (e.g., postcards) Personal communication NR, unclear, other
Diagnostic method	Was the method(s) used for the case definition definitive? a	Radiographic Autopsy Positive mutational analysis	Clinical presentation only	NR Too vague to determine
Numerator	Was reporting of the numerator sufficient (describes any combination of live births, still born, spontaneous abortions/pregnancy terminations)?	The numerator is well described	Not applicable	Numerator is not sufficiently described
Denominator	Was reporting of the denominator sufficient and appropriate?	The denominator is congruent with the numerator in terms of setting and pregnancy outcome	Not applicable	The denominator is not congruent with the numerator Denominator is not sufficiently described
Population size	Was the population size adequate to estimate birth prevalence with 95% confidence? (Naing et al., 2006)	Adequate (≥170,000)	Not adequate for this certainty level (≥100,000–170,000)	<100,000, NR

Abbreviation: NR, not reported.

^aWhen methods varied among sites or across time, the study was assigned the value of the lowest scoring method.