The accuracy of eclampsia cases reported to the Victorian Inpatient Minimum Database and the Perinatal Data Collection Unit

Methodological processes in validating and analysing the quality of population-based data: a case study using the Victorian Perinatal Data Collection

This paper describes methods used and results obtained from a study that measured the accuracy of a routinely collected population-based data set. Data on a random sample of births were extracted from the 2003 Victorian Perinatal Data Collection (VPDC) and compared with information in the original medical record. Accuracy was calculated for 111 items related to diverse aspects of maternity and neonatal health and care. Sensitivity, specificity, positive predictive value and negative predictive value were calculated for dichotomous items. Seventynine items were accurate in at least 97% of cases, 45 of them in at least 99% of cases, and accuracy was below 90% for five items. Very high specificities demonstrate that conditions were rarely reported in error. Lower sensitivities indicate that some events that occurred went unreported on the perinatal form. The excellent results for specifi city indicated that the dataset is appropriate for a conservative analysis of relationships between factors. The lower sensitivities could result in true relationships between factors remaining unidentified. Reasons for discrepancies between the VPDC and the original medical record are described.

Perinatal data collection: current practice in the Australian nursing and midwifery healthcare context

The collection of perinatal data within Queensland, Australia, has traditionally been achieved via a paper form completed by midwives after each birth. Recently, with an increase in the use of e-health systems in healthcare, perinatal data collection has migrated to an online system. It is suggested that this move from paper to an ehealth platform has resulted in improvement to error rates, completion levels, timeliness of data transfer from healthcare institutions to the perinatal data collection and subsequent publication of data items. Worldwide, perinatal data are collected utilising a variety of methods, but essentially data are used for similar purposes: to monitor outcome patterns within obstetrics and midwifery. This paper discusses current practice in relation to perinatal data collection worldwide and within Australia, with a specific focus on Queensland, highlights relevant issues for midwives, and points to the need for further research into the efficient use of an e-health platform for perinatal data collection.

Comparing shingles incidence and complication rates from medical record review and administrative database estimates: how close are they?

Accurate rates of herpes zoster incidence and complication have become of greater interest as studies have suggested an increasing temporal trend in incidence rates across all age groups and long-term follow-up studies of vaccine effectiveness are required by the Food and Drug Administration. This study compares the results obtained from the most commonly used method to obtain herpes zoster data (rates obtained from administrative data) with results obtained when administrative data are supplemented by medical record review. Administrative billing code data identified 1,959 cases of herpes zoster in Olmsted County, Minnesota, adults between January 1, 1996, and December 31, 2001. Of those 1,959 cases, 1,669 (85.2%) could be confirmed by medical record review, a decrease in incidence rate of 14.8%, resulting in a decrease of 0.61/1,000 person-years when adjusted to the US adult population. Complication rates were also significantly different between the 2 methods. It is not clear if the 15% decrease in incidence rates would be seen in every administrative data set or if the lack of confirmation of cases may be variable in both validity and reproducibility between data sets, making estimations in temporal trends and pre/post-vaccine rates difficult to compare across data resources.

The accuracy of reporting of the hypertensive disorders of pregnancy in population health data

OBJECTIVE

To assess the accuracy of hypertensive disorders of pregnancy reporting in birth and hospital discharge data compared with data abstracted from medical records.

METHODS

Data from a validation study of 1200 women provided the 'gold standard' for hypertension status. The validation data were linked to both hospital discharge and birth databases. Hypertension could be reported in one, both, or neither database.

RESULTS

Of the 1184 records available for review, 8.3% of women had pregnancy-related hypertension and 1.3% had chronic hypertension. Reporting sensitivities ranged from 23% to 99% and specificities from 96% to 100%. Using broad rather than specific categories of hypertension and more than one source to identify hypertension improved case ascertainment. Women with severe preeclampsia or adverse outcomes were more likely to have their pregnancy-related hypertension reported. When the hypertension reporting was discordant on the birth and hospital discharge data, the hospital data were more accurate.

CONCLUSIONS

Pregnancy-related hypertension is reported with a reasonable level of accuracy, but chronic hypertension is markedly under-ascertained, even when cases were identified from more than one source. Milder forms of hypertension are more likely to go unreported. Studies utilizing population health data may overestimate the proportion of more severe forms of disease and any risk these conditions contribute to other outcomes.

Quality of diagnosis and procedure coding in ICD-10 administrative data

OBJECTIVES

The International Classification of Disease, 10th Revision (ICD-10) was introduced worldwide beginning in the late 1990s. Because there have been no published data on the quality of coding using ICD-10, the aim of our analysis is to assess the quality of ICD-10 coding in routinely collected hospital discharge data from Australia, which began using ICD-10 in 1998.

METHODS

Audit data from the years 1998-1999 (n = 7004) and 2000-2001 (n = 7631), excluding same-day chemotherapy and dialysis cases, were used in data analysis. Quality measures included prevalence comparisons, sensitivity, positive predictive value (PPV), and the kappa statistic.

RESULTS

Comparison of the audit sample to public hospital discharges showed little difference in age and gender, with audited cases more likely to be overnight stays. There was no difference in the median number of hospital assigned diagnosis and procedure codes per discharge. Agreement of the principal diagnosis code was 85% at the 3-digit level and 79% at the 4-digit level in 1998-1999; this rate had improved to 87% and 81% in 2000-2001. Principal procedure code agreement was 85% in 1998-1999 and 83% in 2000-2001 at the 5-digit level, and 81% and 80% at the 7-digit level, respectively. Specific major diagnoses, comorbid diagnoses, major procedures, and minor procedures showed good-to-excellent coding quality.

CONCLUSIONS

The transition to ICD-10 has occurred with no loss of data quality, with data showing a high level of reliability and adherence to coding standards. When consideration is given to the nature of the analysis, administrative data can provide highly reliable population-based estimates of hospitalization rates.

Validation of the Victorian Perinatal Morbidity Statistics form: new items, pre-coded text and free text

This study assessed the quality of information on the form used by the Victorian Perinatal Data Collection Unit. Information relating to four new and one modified data items, and to pre-coded and free text regions relating to maternal morbidity, was compared with that in the medical record. The new data items were documented correctly on 95.5% of forms, as were 67% of pre-coded conditions. Between 53% and 75% of free text items were correctly recorded. The results highlight the need for information and education sessions for midwives and other staff in order to collect and maintain high quality data.

Perinatal and obstetric outcomes of donor insemination using cryopreserved semen in Victoria, Australia

This study compared the perinatal and obstetric outcomes of 1552 donor insemination pregnancies in Victoria, Australia, with a control group of 7717 normally conceived pregnancies from the general population. Data on the outcomes of pregnancies of at least 20 weeks gestation, for both groups, were obtained from the same population-based birth registry. The study showed that there were no significant differences between the donor insemination and control groups in the incidence of preterm birth, low birthweight, multiple birth, perinatal death and birth defects, or in the sex ratio. Pregnancies conceived by donor insemination were significantly more likely than controls to have an induced labour (OR = 1.6, 95% CI 1. 4-1.8), a forceps delivery (OR = 1.5, 95% CI 1.3-1.8) and/or a Caesarean section (OR = 1.6, 95% CI 1.4-1.9) and to develop pre-eclampsia (OR = 1.4, 95% CI 1.2-1.8) after adjusting for maternal age, multiple birth, parity and presentation. Reasons for the higher rate of induced and operative deliveries are not clear. Overall, the study's findings are reassuring for couples considering infertility treatment with donor insemination. The study illustrates the importance of complete follow-up in studies of pregnancy outcomes after assisted conception and the use of appropriate population-based control groups with comparable ascertainment of outcomes.