Table 4.
Odds ratios and 95% confidence intervals for the odds of infant leukaemia by data source
| Characteristica | Medical record data
|
Maternal telephone interview data
|
Bootstrap ratio
|
||||||
|---|---|---|---|---|---|---|---|---|---|
| Cases (n = 234) n (%) | Noncases (n = 215) n (%) | Bootstrap ORb [95% CI] | Cases (n = 234) n (%) | Noncases (n = 215) n (%) | Bootstrap ORb [95% CI] | Bootstrap ORadjustedc [95% CI] | Unadjusted ORs for interview vs. medical recordd [95% CI]; P-valuee | ORs for adjusted interview vs. unadjusted medical record ORf [95% CI]; P-valuee | |
| Gestational diabetes | |||||||||
| Yes | 4 (2) | 6 (3) | 0.66 [0.14, 3.02] | 7 (3) | 11 (5) | 0.59 [0.20, 1.75] | 0.98 [0.34, 2.81] | 0.89 [0.25, 3.24]; P = 0.86 | 1.49 [0.40, 5.58]; P = 0.55 |
| No | 207 (98) | 195 (97) | 227 (97) | 203 (95) | |||||
| Hypertension | |||||||||
| Yes | 30 (14) | 21 (10) | 1.39 [0.75, 2.56] | 30 (13) | 36 (17) | 0.74 [0.43, 1.27] | 0.77 [0.44, 1.36] | 0.53 [0.30, 0.95]; P = 0.03 | 0.55 [0.30, 1.02]; P = 0.06 |
| No | 190 (86) | 186 (90) | 202 (87) | 179 (83) | |||||
| Protein or albumin in urine | |||||||||
| Yes | 157 (73) | 151 (74) | 0.95 [0.61, 1.48] | 22 (9) | 18 (8) | 1.13 [0.57, 2.22] | 1.02 [0.49, 2.13] | 1.19 [0.56, 2.54]; P = 0.66 | 1.07 [0.48, 2.42]; P = 0.87 |
| No | 57 (27) | 52 (26) | 210 (91) | 195 (92) | |||||
| Peripheral oedema | |||||||||
| Yes | 78 (46) | 65 (40) | 1.28 [0.82, 1.98] | 148 (63) | 132 (61) | 1.08 [0.73, 1.60] | 0.92 [0.61, 1.39] | 0.85 [0.53, 1.37]; P = 0.50 | 0.72 [0.44, 1.18]; P = 0.20 |
| No | 93 (54) | 99 (60) | 86 (37) | 83 (39) | |||||
| Toxaemia or pre-eclampsia | |||||||||
| Yes | 15 (7) | 7 (3) | 2.05 [0.73, 5.70] | 12 (5) | 8 (4) | 1.34 [0.49, 3.70] | 1.20 [0.43, 3.35] | 0.66 [0.24, 1.81]; P = 0.42 | 0.58 [0.21, 1.61]; P = 0.30 |
| No | 197 (93) | 198 (97) | 222 (95) | 207 (96) | |||||
| Delivery method | |||||||||
| Caesarean section | 59 (26) | 44 (21) | 1.34 [0.85, 2.09] | 60 (26) | 44 (20) | 1.34 [0.86, 2.09] | 1.41 [0.87, 2.27] | 1.01 [0.96, 1.05]; P = 0.82 | 1.05 [0.90, 1.23]; P = 0.50 |
| Vaginal | 170 (74) | 169 (79) | 174 (74) | 171 (80) | |||||
| Infant received supplemental oxygen | |||||||||
| Yes | 34 (46) | 51 (43) | 1.14 [0.63, 2.05] | 22 (10) | 26 (12) | 0.77 [0.41, 1.43] | 0.84 [0.44, 1.62] | 0.68 [0.32, 1.45]; P = 0.32 | 0.74 [0.34, 1.65]; P = 0.47 |
| No | 40 (54) | 68 (57) | 208 (90) | 189 (88) | |||||
| Infant moved for special treatment | |||||||||
| Yes | 15 (19) | 16 (11) | 1.92 [0.87, 4.27] | 29 (13) | 23 (11) | 1.19 [0.65, 2.16] | 1.27 [0.68, 2.35] | 0.62 [0.31, 1.23]; P = 0.17 | 0.66 [0.32, 1.37]; P = 0.26 |
| No | 63 (81) | 129 (89) | 203 (88) | 192 (89) | |||||
OR, odds ratio; CI, confidence interval.
Odds ratios calculated for those characteristics with all cells of 2 × 2 tables >3.
Bootstrap odds ratio estimates from 10 000 resamplings.
Bootstrap odds ratio estimate for odds ratio adjusted for length of time in years (continuous variable) between index child’s birth and completion of telephone interview.
Bootstrap ratio of unadjusted telephone interview odds ratio to unadjusted medical record odds ratio.
Two-sided P-value testing whether the telephone interview data differ from the medical record data using a z-score.
Bootstrap ratio of adjusted telephone interview odds ratio to unadjusted medical record odds ratio.
Notes. Numbers for cases and noncases are not identical for the telephone interview and medical record due to missing data (not recorded in medical record or during interview) and/or data not known (i.e. ‘don’t know’ response) by mothers during telephone interview. Percentages may not add to 100% due to rounding.