The Canadian Assisted Reproductive Technologies Register (CARTR) Plus database: a validation study

Abstract

Study question: Are data accurately documented in the Canadian Assisted Reproductive Technologies Register (CARTR) Plus database?

Summary answer: Measures of validity were strong for the majority of variables evaluated while those with moderate agreement were FSH levels, oocyte origin and elective single embryo transfer.

What is known already: Health databases and registries are excellent sources of data. However, as these databases are typically not established for the primary purpose of performing research, they should be evaluated prior to utilization for research both to inform the study design and to determine the extent to which key study variables, such as patient characteristics or therapies provided, are accurately documented in the database. CARTR Plus is Canada's national register for collecting extensive information on IVF and corresponding pregnancy outcomes, and it has yet to be validated.

Study design size duration: This study evaluating the data translation CARTR Plus database examined IVF cycles performed in 2015 using data directly from patient charts. Six clinics across Canada were recruited to participate, using a purposive sampling strategy. Fixed random sampling was employed to select 146 patient cycles at each clinic, representing unique patients. Only a single treatment cycle record from a unique patient at each clinic was considered during chart selection.

Participants/materials setting methods: Twenty-five data elements (patient characteristics, treatments and outcomes) were reabstracted from patient charts, which were declared the reference standard. Data were reabstracted by two independent auditors with relevant clinical knowledge after confirming inter-rater reliability. These data elements from the chart were then compared to those in CARTR Plus. To determine the validity of these variables, we calculated kappa coefficients, sensitivity, specificity, positive predictive value and negative predictive value with 95% CI for categorical variables and calculated median differences and intraclass correlation coefficients (ICC) for continuous variables.

Main results and the role of chance: Six clinics agreed to participate in this study representing five Canadian provinces. The mean age of patients was 35.5 years, which was similar between the two data sources, resulting in a near perfect level of agreement (ICC = 0.99; 95% CI: 0.99, 0.99). The agreement for FSH was moderate, ICC = 0.68 (95% CI: 0.64, 0.72). There was nearly perfect agreement for cycle type, kappa = 0.99 (95% CI: 0.98, 1.00). Over 90% of the cycles in the reabstracted charts used autologous oocytes; however, data on oocyte source were missing for 13% of cycles in CARTR Plus, resulting in a moderate degree of agreement, kappa = 0.45 (95% CI, 0.37, 0.52). Embryo transfer and number of embryos transferred had nearly perfect agreement, with kappa coefficients greater than 0.90, whereas that for elective single or double embryo transfer was much lower (kappa = 0.55; 95% CI: 0.49, 0.61). Agreement was nearly perfect for pregnancy type, and number of fetal sacs and fetal hearts on ultrasound, all with kappa coefficients greater than 0.90.

Large-scale data: N/A.

Limitations reasons for caution: CARTR Plus contains over 200 variables, of which only 25 were assessed in this study. This foundational validation work should be extended to other CARTR Plus database variables in future studies.

Wider implications of the findings: This study provides the first assessment of the quality of the data translation process of the CARTR Plus database, and we found very high quality for the majority of the variables that were analyzed. We identified key data points that are either too often lacking or inconsistent with chart data, indicating that changes in the data entry process may be required.

Study funding/competing interests: This study was funded by Canadian Institutes of Health Research (CIHR) (Grant Number FDN-148438) and by the Canadian Fertility and Andrology Society Research Seed Grant (Grant Number: N/A). The authors report no conflict of interest.

Trial registration number: Not applicable.

Keywords: ART; database; infertility; quality assurance; reproductive epidemiology; validation.