Table 3.
Quality Appraisal of Included Articles
| Domain | Quality Items, Potential Bias | Yes | No | Not Stated | Number of Studies, % |
|---|---|---|---|---|---|
| Study ascertainment | The study population is adequately described for key characteristics (ie, CHD subtype frequency, sex distribution, ethnicity) | 21, 22, 23, 25, 27, 29, 30, 33, 34 | 20, 24, 26, 27, 28, 31, 32, 35 | 9 (56%) | |
| Ascertainment is adequately described, including method of ascertainment included birth years, study location | 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35 | 16 (100%) | |||
| Inclusion and exclusion criteria are adequately described (ie, ICD codes stated and inclusion of extracardiac anomalies | 21, 22, 23, 24, 25, 26, 27, 29, 30, 32, 33, 34, 35 | 20, 27, 28, 31 | 13 (81%) | ||
| There is adequate ascertainment | 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35 | 16 (100%) | |||
| POTENTIAL BIAS: The study sample represents the population of interest on key characteristics sufficient to limit potential bias to the results | 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35 | 16 (100%) | |||
| Study attrition | The proportion of traced cases is stated and adequate | 20, 22, 23, 29, 32 | 21, 24, 25, 26, 27, 28, 30, 31, 33, 34, 35 | 5 (31%) | |
| Reasons for untraced cases are provided | 20, 23, 29, 32 | 22 | 21, 24, 25, 26, 27, 28, 30, 31, 33, 34, 35 | 4 (25%) | |
| Untraced cases are adequately described for key characteristics (ie, CHD subtype) | 20, 22, 23, 29, 32 | 21, 24, 25, 26, 27, 28, 30, 31, 33, 34, 35 | 5 (31%) | ||
| There are no important differences between key characteristics and outcomes in participants who were traced and untraced | 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35 | 0 (0%) | |||
| POTENTIAL BIAS: Untraced cases are not associated with key characteristics (ie, the study data adequately represent the sample), sufficient to limit potential bias | 20, 22, 23, 29, 32 | 21, 24, 25, 26, 27, 28, 30, 31, 33, 34, 35 | 5 (31%) | ||
| Outcome ascertainment | Frequency of outcome is recorded | 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 32, 33, 34, 35 | 30, 31 | 14 (88%) | |
| The method of ascertainment of deaths is valid and reliable to limit misclassification bias | 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35 | 25 | 15 (94%) | ||
| POTENTIAL BIAS: The outcome of interest is adequately measured in study participants to sufficiently limit potential bias | 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35 | 25 | 15 (94%) | ||
| Analysis | There is sufficient presentation of results (ie, number of cases and 95% CIs) | 21, 24, 25, 27, 29, 30, 31, 32, 33, 34, 35 | 20, 22, 23, 26, 27, 28 | 11 (69%) | |
| The analysis is adequate for the design of the study | 20, 21, 24, 25, 27, 28, 29, 30, 31, 32, 33, 34, 35 | 22, 23, 26 | 13 (81%) | ||
| Results are not selectively reported | 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35 | 16 (100%) | |||
| POTENTIAL BIAS: The statistical analysis is appropriate for the design of the study, limiting potential for presentation of invalid results | 20, 21, 24, 25, 27, 28, 29, 30, 31, 32, 33, 34, 35 | 22, 23, 26 | 13 (81%) |
CHD indicates congenital heart disease; ICD, International Classification of Disease.