Background
Health data registers and quality registers
The Swedish Maternal Health Care Register
Aims
Methods
Study design and study sample
Medical records of pregnancy, delivery, and the postpartum period
Data collection procedures
Study protocol
Presentation of included variables
First data entry | Second data entry | |
---|---|---|
Data collected at first visit in antenatal care (ANC) | Data collected at postpartum visit in antenatal care (ANC) 4 to 16 weeks after delivery | |
Variables
|
Variables
|
Variables
|
Date of first visit in ANC
a
|
Live born child
| Treatment of psychiatric disorder |
Country of birth | Still birth/termination of pregnancy | Questioned about exposure to violence |
No. of previous deliveries
| Date of delivery estimated by ultrasound |
Oral glucose tolerance test (OGTT) performed
|
Maternal weight (kilograms)
b
|
Estimated date of delivery (ultrasound)
|
2-hour value of plasma glucose at OGTT (mmol/L)
|
Maternal height (centimetres)
b
| Estimated date of delivery (last menstruation) | Diagnosis of gestational diabetes mellitus (GDM) |
Smoking three months prior to pregnancy |
Ultrasound examination at gestational age 16-21 week
|
Date of delivery
|
No. of cigarettes/day three months prior to pregnancy |
Combined Ultrasound and Biochemical screening (CUB)
| Maternal age at delivery |
Smoking at first ANC visit
|
Second trimester serum screening
|
Mode of delivery
|
No. of cigarettes/day at first ANC visit |
Chorionic villus sampling (CVS)
|
If caesarean section, elective or emergency section
|
Use of snuff three months prior to pregnancy |
Amniocentesis (AC)
|
Singleton birth/multiple births
|
Use of snuff at first ANC visit
|
Number of antenatal visits until estimated date of delivery (determined by ultrasound)
|
Birth weight (grams)
c, d
|
Assessment of use of alcohol prior to pregnancy with screening instrument Alcohol Use Disorder Identification Test (AUDIT)
| Number of midwives surveying the pregnant woman in ANC |
Gender of infant
d
|
AUDIT-score
| Use of authorized interpreter | Documented suspicion of intrauterine growth retardation |
Education level |
Smoking at 32 weeks of gestation
| Postpartum visit at ANC |
Employment status | No. of cigarettes/day at 32 gestational weeks | Date of postpartum visit at ANC |
Self-rated health prior to pregnancy |
Use of snuff at 32 weeks of gestation
| Maternal body weight at postpartum visit at ANC (kilograms) |
Maternal weight (in kilograms), last data entry after 35 gestational weeks
| Self-rated health during pregnancy | |
Participated in prenatal education group (pregnant woman) | Self-rated health postpartum | |
Participated in prenatal education group (partner) | Breast feeding at 4 weeks postpartum | |
Counselling due to fear of childbirth |
Control of data registered in the protocol
Statistical analysis
Results
Background presentation
City | Participating hospital | Level of health care | Inhabitants/km22011a
| No. of births 2011b(%)c
| No. of medical records (%)d
|
---|---|---|---|---|---|
Göteborg | Sahlgrenska University Hospital | University | 66.8 | 10363 (9.4) | 91 (10.4) |
Halmstad | Halmstad Hospital | County | 55.6 | 1799 (1.6) | 96 (10.9) |
Jönköping | Ryhov Hospital | County | 32.4 | 2075 (1.9) | 99 (11.3) |
Stockholm | Karolinska University Hospital | University | 320.5 | 4642 (4.2) | 96 (10.9) |
Stockholm | Södersjukhuset | University | 320.5 | 7331 (6.7) | 98 (11.2) |
Sundsvall | Sundsvall Hospital | Regional | 11.2 | 1536 (1.4) | 100 (11.4) |
Umeå | Umeå University Hospital | University | 4.7 | 1817 (1.6) | 100 (11.4) |
Örebro | Örebro University Hospital | University | 33.1 | 2867 (2.6) | 99 (11.3) |
Östersund | Östersund Hospital | Regional | 2.6 | 1298 (1.2) | 99 (11.3) |
30728 (28.0) | 878 (100%) |
Degree of coverage of data in medical records and in the MHCR
Variable | Data source: Medical records | Data source: MHCR | Data available in both data sources | Identical information in both data sources | Correlationa
| Sensitivity | Specificity | ||||
---|---|---|---|---|---|---|---|---|---|---|---|
n | % | n | % | n | % | n | % | ||||
Variables collected at first antenatal care (ANC) visit
| |||||||||||
Date of first visit in ANC (numerical) | 877 | 99.9 | 868 | 98.9 | 867 | 98.7 | 685 | 79.0 | 0.878 (S) | ||
No of previous deliveries (numerical) | 878 | 100 | 867 | 98.7 | 867 | 98.7 | 840 | 96.8 | 0.971 (P) | ||
Maternal weight at first ANC visit (numerical) | 862 | 98.1 | 855 | 97.4 | 847 | 96.4 | 798 | 94.2 | 0.990 (P) | ||
Maternal height (numerical) | 872 | 99.3 | 862 | 98.2 | 860 | 97.9 | 834 | 97.0 | 0.982 (P) | ||
Smoking at first ANC visit (Yes/No) | 875 | 99.7 | 872 | 99.2 | 868 | 98.9 | 843 | 97.1 | 0.742 (C) | 0.650 | 0.995 |
Use of Snuff at first ANC visit (Yes/No) | 878 | 100 | 871 | 99.2 | 871 | 99.2 | 861 | 98.9 | 0.540 (C) | 0.429 | 0.998 |
Assessment of alcohol screening prior to pregnancy (AUDIT) (Yes/No) | 802 | 91.3 | 859 | 97.8 | 788 | 89.7 | 691 | 87.7 | 0.480 (C) | 0.986 | 0.393 |
If Yes, AUDIT score (numerical)b
| 650/643 | 98.9 | 777/771 | 99.2 | 621 | 95.5 | 600 | 96.6 | 0.989 (P) | ||
Variables collected at 4 to 16 weeks postpartum
| |||||||||||
Prenatal diagnostics | |||||||||||
Amniocentesis (AC) (Yes/No) | 875 | 99.7 | 791 | 90.1 | 788 | 89.7 | 772 | 98.0 | 0.754 (C) | 0.743 | 0.991 |
Chorion Villus Sampling (CVS) (Yes/No) | 875 | 99.7 | 790 | 90.0 | 787 | 89.6 | 778 | 98.9 | 0.176 (C) | 0.167 | 0.995 |
Combined Ultrasound and Biochemical screening (CUB) (Yes/No) | 780 | 88.8 | 791 | 90.1 | 700 | 89.7 | 665 | 95.1 | 0.888 (C) | 0.936 | 0.957 |
Second trimester Serum Screening (Yes/No) | 849 | 96.7 | 790 | 90.0 | 767 | 87.4 | 671 | 87.4 | 0.002 (C) | 0.043 | 0.958 |
Ultrasound examination at 16 – 21 gestational weeks (Yes/No) | 862 | 98.2 | 791 | 90.1 | 779 | 88.6 | 755 | 96.9 | 0.064 (C) | 0.979 | 0.800 |
Estimated date of delivery (ultrasound) (numerical)c
| 871 | 99.2 | 874 | 99.5 | 868 | 98.9 | 781 | 90.0 | 0.946 (S) | ||
Oral Glucose Tolerance Test (OGTT) performed (Yes/No) | 869 | 98.9 | 877 | 99.9 | 868 | 98.9 | 842 | 97.0 | 0.854 (C) | 0.880 | 0.982 |
If Yes, 2-hour value of plasma glucose at OGTT (numerical)d
| 100/48 | 48.0 | 104/97 | 93.3 | 46 | 46.0 | 34 | 73.9 | 0.902 (P) | ||
Smoking at 32 gestational weeks (Yes/No) | 858 | 97.7 | 876 | 99.8 | 856 | 97.5 | 849 | 99.1 | 0.864 (C) | 0.821 | 0.998 |
Use of Snuff at 32 gestational weeks (Yes/No) | 832 | 94.8 | 876 | 99.8 | 830 | 94.5 | 826 | 99.5 | 0.712 (C) | 0.625 | 0.999 |
Maternal weight, last data entry after 35 gestational weeks (numerical) | 777 | 88.5 | 843 | 96.0 | 760 | 86.6 | 706 | 92.9 | 0.989 (P) | ||
No. of ANC visits until estimated date of delivery (numerical) | 877 | 99.9 | 868 | 98.9 | 867 | 98.7 | 627 | 72.3 | 0.915 (P) | ||
Date of delivery (numerical) | 878 | 100 | 878 | 100 | 878 | 100 | 842 | 95.9 | 0.989 (S) | ||
Live born child (Yes/No) | 878 | 100 | 878 | 100 | 878 | 100 | 874 | 99,5 | 0.598 (C) | 0.999 | 0.500 |
Birth weight (numerical) | 876 | 99.8 | 869 | 99.0 | 868 | 98.9 | 813 | 93.7 | 0.989 (P) | ||
Gender of infant (Boy/Girl/Sex unknown) | 878 | 100 | 874 | 99.5 | 874 | 99.5 | 862 | 99.2 | 0.973 (C) | ||
Singleton birth/multiple births | 877 | 99.9 | 878 | 100 | 877 | 99.8 | 875 | 99.7 | 0.908 (C) | ||
Mode of delivery (vaginal/instrumental vaginal/caesarean section) | 876 | 99.8 | 876 | 99.8 | 874 | 99.5 | 857 | 98.0 | 0.946 (C) | ||
If caesarean section, elective CS/emergency CSe
| 130/115 | 88.5 | 129/128 | 99.2 | 110 | 84.6 | 102 | 92.7 | 0.841 (C) |
Agreement of data in medical records and in the MHCR
Variable | Medical recordsa
| Medical records re-collectionb
| Data available in both data sources | Identical information in both data sources | Correlationc
| 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) |