Predictors of disease activity during pregnancy in women with inflammatory bowel disease-a Danish cohort study.

BACKGROUND AND AIMS: Inflammatory bowel disease (IBD) activity during pregnancy is associated with adverse pregnancy outcomes. We aimed to identify key clinical characteristics that predict disease activity during pregnancy. METHODS: Between January 2008 through 2021, we identified all singleton pregnancies among women with IBD recorded in patient and birth registries at a tertiary IBD centre in Denmark. Maternal and infant data were retrieved from medical records. Demographics, Physicians Global Assessment (PGA) of disease activity 6 months prior to pregnancy and in all three trimesters of pregnancy and pregnancy outcomes were recorded. RESULTS: In 609 pregnancies, we observed 603 (99.0%) live births. Disease activity in one or more trimesters was seen in 283 women (46.5%). UC phenotype was associated with an increase in risk of disease activity (adjusted OR = 2.6 [1.8-3.9]; p < 0.001). Disease activity within 6 months prior to conceiving (169 women [27.7%]) was associated with an increased risk of continuous disease activity during pregnancy (adjusted OR of 5.3 [3.5-8.2]; p < 0.001). Disease activity during a previous pregnancy was associated with an increased risk of flares in subsequent pregnancies (adjusted OR of 3.2 [1.5-6.6]; p = 0.002). Sustained clinical remission throughout pregnancy was associated with an increased probability of normal birth term, birthweight and low risk of fetal growth restriction (FGR) and stillbirth. CONCLUSION: Predictors for disease activity include disease activity in a previous pregnancy and/or prior to conception, as well as UC phenotype. Reassuringly, women with IBD in remission are not at increased risk of adverse pregnancy outcomes.

Defining measures of kidney function in observational studies using routine health care data: methodological and reporting considerations.

The availability of electronic health records and access to a large number of routine measurements of serum creatinine and urinary albumin enhance the possibilities for epidemiologic research in kidney disease. However, the frequency of health care use and laboratory testing is determined by health status and indication, imposing certain challenges when identifying patients with kidney injury or disease, when using markers of kidney function as covariates, or when evaluating kidney outcomes. Depending on the specific research question, this may influence the interpretation, generalizability, and/or validity of study results. This review illustrates the heterogeneity of working definitions of kidney disease in the scientific literature and discusses advantages and limitations of the most commonly used approaches using 3 examples. We summarize ways to identify and overcome possible biases and conclude by proposing a framework for reporting definitions of exposures and outcomes in studies of kidney disease using routinely collected health care data.

Defining Baseline Creatinine for Identification of AKI in Population-Based Laboratory Databases: A Danish Nationwide Cohort Study.

Background: The baseline creatinine level is central in the Kidney Disease Improving Global Outcomes (KDIGO) criteria of AKI, but baseline creatinine is often inconsistently defined or unavailable in AKI research. We examined the rate, characteristics, and 30-day mortality of AKI in five AKI cohorts created using different definitions of baseline creatinine. Methods: This nationwide cohort study included all individuals aged ≥18 years in Denmark with a creatinine measurement in 2017. Applying the KDIGO criteria, we created four AKI cohorts using four different baseline definitions (most recent, mean, or median value of outpatient creatinine 365-368 days before, or median value 90-98 days before, if available, otherwise median value 365-391 days before) and one AKI cohort not using a baseline value. AKI rate and the distribution of age, sex, baseline creatinine, and comorbidity were described for each AKI cohort, and the 30-day all-cause mortality was estimated using the Kaplan-Meier method. Results: The study included 2,095,850 adults with at least one creatinine measurement in 2017. The four different baseline definitions identified between 61,189 and 62,597 AKI episodes. The AKI rate in these four cohorts was 13-14 per 1000 person-years, and 30-day all-cause mortality was 17%-18%. The cohort created without using a baseline creatinine included 37,659 AKI episodes, corresponding to an AKI rate of 8.2 per 1000 person-years and a 30-day mortality of 23%. All five cohorts were similar regarding age, sex, and comorbidity. Conclusions: In a population-based setting with available outpatient baseline creatinine, different baseline creatinine definitions revealed comparable AKI cohorts, whereas the lack of a baseline creatinine when defining AKI led to a smaller AKI cohort with a higher mortality. These findings underscore the importance of availability and consistent use of an outpatient baseline creatinine, particulary in studies of community-acquired AKI.