Table 2. Cohort studies included in the meta-analysis.
| Author (year) | Number of exposed children | Calculation of expected cases (EC) | Observed/expected cases (N) | Standardized incidence ratio (95%CI) |
|---|---|---|---|---|
| White et al (1990) | 2285 | No calculation in the original study. EC calculated by applying cancer incidence rates from the original study to the IVF cohort | 3/0.13 | 23.08 (8.38–67.31) |
| Rufat et al (1994) | 1637 | No calculation in the original study. EC calculated by applying published cancer incidence rates (Bernard et al, 1993; Gembara et al, 1995) to the IVF cohort | 1/0.7 | 1.43 (0.31–3.79) |
| Doyle et al (1998) | 2507 | Application of cumulative national cancer rates, taking into account year of birth and length of follow-up | 2/3.5 | 0.57 (0.07–2.06) |
| Bruinsma et al (2000) | 5249 | Application of the Victorian cancer incidence rates, taking into account age and length of follow-up | 6/4.33 | 1.39 (0.62–3.09) |
| Lerner-Geva et al (2000) | 332 | Application of specific national cancer incidence rates, taking into account age, gender and year of diagnosis | 0/1.7 | 0 (0–2.18)a |
| Klip et al (2001) | 9050b | Application of cancer incidence rates from the Eindhoven and the Netherlands Cancer Registries, taking into account age, gender and calendar period | 6/6.78 | 0.88 (0.41–1.98) |
| Ericson et al (2002) | 9056 | Application of the Swedish Cancer Registry cancer incidence rates, taking into account year of birth, maternal age, parity and length of involuntary childlessness | 11/12.5 | 0.88 (0.5–1.13) |
| Odone-Filho et al (2002) | Around 2000 | Application of annual incidence rate of cancer for children aged 0–4 years | 4/1.17 | 3.42 (1.42–8.76) |
| Moll et al (2003) | Not known | Application of the 1-year age-specific mortality rates from statistics in the Netherlands | 5/0.69 | 7.25 (3.19–17.03) |
| Pinborg et al (2004a, 2004b) | 8523 | No calculation in the original study. EC calculated by applying the 0–6 years cancer incidence rates from the Danish Cancer Registry to the IVF cohort | 9/6.7 | 1.34 (0.71–1.78) |
| Bradbury and Jick (2004) | 176 | No calculation in the original study. EC were calculated by applying retinoblastoma incidence rates from the original study to the IVF cohort | 0/0.01 | 0 (0–7.40)a |
a
The upper confidence limit was calculated using 0.5 as observed number of cases.
b
In all, 429 children conceived after hormonal treatment, but not after ART, were excluded.