Table 4.
Comparison between primary collection and re-collection of data from medical records using correlation analysis, and analysis of sensitivity and specificity for binary variables
| Variable | Medical records a | Medical records re-collection b | Data available in both data sources | Identical information in both data sources | Correlation c | Sensitivity | Specificity | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| n | % | n | % | n | % | n | % | ||||
| Variables collected at first antenatal care (ANC) visit | |||||||||||
| Date of first visit in ANC (numerical) | 150 | 100 | 150 | 100 | 150 | 100 | 116 | 77.3 | 0.773 (S) | ||
| No of previous deliveries (numerical) | 150 | 100 | 150 | 100 | 150 | 100 | 149 | 99.3 | 0.988 (P) | ||
| Maternal weight at first ANC visit (numerical) | 147 | 98.0 | 148 | 98.7 | 147 | 99.3 | 146 | 99.3 | 0.995 (P) | ||
| Maternal height (numerical) | 149 | 99.3 | 149 | 99.3 | 149 | 100 | 148 | 99.3 | 1.000 (P) | ||
| Smoking at first ANC visit (Yes/No) | 149 | 99.3 | 149 | 99.3 | 149 | 100 | 148 | 99.3 | 0.794 (C) | d | 1.000 |
| Use of Snuff at first ANC visit (Yes/No) | 150 | 100 | 150 | 100 | 150 | 100 | 146 | 97.3 | 0.793 (C) | 0.667 | 1.000 |
| Assessment of alcohol screening prior to pregnancy (AUDIT) (Yes/No) | 130 | 86.7 | 130 | 86.7 | 130 | 86.7 | 121 | 93.1 | 0.729 (C) | 0.972 | 0.136 |
| If Yes, AUDIT score (numerical)e | 113/109 | 96.5 | 108/106 | 98.1 | 102 | 90.3 | 100 | 98.0 | 0.987 (P) | ||
| Variables collected at 4 to 16 weeks postpartum | |||||||||||
| Prenatal diagnostics | |||||||||||
| Amniocentesis (AC) (Yes/No) | 150 | 100 | 150 | 100 | 150 | 100 | 150 | 100 | 1.000 (C) | 1.000 | 0.983 |
| Chorion Villus Sampling (CVS) (Yes/No) | 150 | 100 | 150 | 100 | 150 | 100 | 150 | 100 | 1.000 (C) | d | 0.992 |
| Combined Ultrasound and Biochemical screening (CUB) (Yes/No) | 147 | 98.0 | 149 | 99.3 | 147 | 98.6 | 142 | 96.6 | 0.912 (C) | 0.919 | 0.941 |
| Second trimester Serum Screening (Yes/No) | 148 | 98.7 | 150 | 100 | 148 | 98.7 | 148 | 100 | f | ||
| Ultrasound examination at 16 – 21 gestational weeks (Yes/No) | 147 | 98.0 | 147 | 98.0 | 147 | 98.0 | 145 | 99.0 | 0.246 (C) | 0.975 | d |
| Estimated date of delivery (ultrasound) (numerical)g | 147 | 100 | 147 | 100 | 147 | 100 | 145 | 98.7 | 0.955 (S) | ||
| Oral Glucose Tolerance Test (OGTT) performed (Yes/No) | 149 | 99.3 | 149 | 99.3 | 148 | 98.0 | 144 | 98.0 | 0.819 (C) | 1.000 | 0.986 |
| If Yes, 2-hour value of plasma glucose at OGTT (numerical)h | 13/10 | 77.0 | 10/9 | 90.0 | 9 | 69.2 | 9 | 100 | 1.000 (P) | ||
| Smoking at 32 gestational weeks (Yes/No) | 145 | 96.7 | 145 | 96.7 | 145 | 100 | 145 | 100 | 1.000 (C) | 1.000 | 1.000 |
| Use of Snuff at 32 gestational weeks (Yes/No) | 145 | 96.7 | 145 | 96.7 | 145 | 100 | 144 | 99.3 | 0.797 (C) | 1.000 | 1.000 |
| Maternal weight, last data entry after 35 gestational weeks (numerical) | 142 | 94.7 | 141 | 94.0 | 141 | 99.3 | 137 | 97.2 | 1.000 (P) | ||
| No. of ANC visits until estimated date of delivery (numerical) | 150 | 100 | 150 | 100 | 150 | 100 | 96 | 64.0 | 0.890 (P) | ||
| Date of delivery (numerical) | 150 | 100 | 150 | 100 | 150 | 100 | 149 | 99.3 | 0.975 (S) | ||
| Live born child (Yes/No) | 150 | 100 | 150 | 100 | 150 | 100 | 150 | 100 | f | 1.000 | 1.000 |
| Birth weight (numerical) | 150 | 100 | 150 | 100 | 150 | 100 | 140 | 93.3 | 0.997 (P) | ||
| Gender of infant (Boy/Girl/Sex unknown) | 150 | 100 | 150 | 100 | 150 | 100 | 149 | 99.3 | 0.987 (C) | ||
| Singleton birth/multiple births | 150 | 100 | 150 | 100 | 150 | 100 | 150 | 100 | 1.000 (C) | ||
| Mode of delivery (vaginal/instrumental vaginal/caesarean section) | 150 | 100 | 150 | 100 | 150 | 100 | 149 | 99.3 | 0.983 (C) | ||
| If caesarean section, elective CS/emergency CSi | 23/22 | 95.7 | 23/23 | 100 | 22 | 95.7 | 22 | 100 | 1.000 (C) | ||
aPrimary collection of data from medical records.
bRe-collection of data from medical records.
cCorrelation analysis: C = Cohen’s kappa, P = Pearson´s correlation coefficient, S = Spearman`s correlation coefficient.
dSensitivity or specificity not possible to calculate since one or more of the cells in the calculation includes zero.
eMeasures are calculated for those who have undergone alcohol screening. The denominator is the total no of “Yes” responses. Denominator in the Medical records (n = 113), denominator in the MHCR (n = 108).
fCohen’s kappa is not calculated as one of the variables is a constant.
gMeasures are calculated for those who have undergone ultrasound.
hMeasures are calculated for those who have undergone OGTT. The denominator is the total no of “Yes” responses. Denominator for the medical records (n = 13), denominator for the MHCR (n = 10).
iMeasures are calculated for those who have undergone caesarean section. The denominator is the total no of “Yes” responses. Denominator for the medical records (n = 23), denominator for the MHCR (n = 23).