To assess the validity of the diagnoses of atrial fibrillation (AF) and atrial flutter (AFL) for men and women recorded in the Danish National Patient Registry, and to assess the relative distribution of AF and AFL. Review of medical records for incident cases of AF and/or AFL in the Diet, Cancer, and Health cohort study. Participants were enrolled in 1993-97 with 13.6 years of follow-up until 30 December, 2009. The positive predictive value of the combined diagnosis of AF and/or AFL was 92.6% (95% CI 88.8%; 95.2%) with no significant difference between sexes (men 93.7% (133/142), women 90.8% (129/142)). The proportion of AFL either alone or in combination with AF was significantly higher in men than in women (13.5% (18/133) vs. 5.4% (7/129), p =0.03). The positive predictive value of the specified diagnosis of AFL was 57.5% for men (46/80) and 29.6% for women (8/27). This study shows that the validity of the diagnosis of AF and/or AFL is high and may be used for registry-based studies. A specified diagnosis of AFL was rarely used and was not reliable to distinguish between cases of AF and AFL.

We propose a nonstationary state space model for multivariate longitudinal count data driven by a latent gamma Markov process. The Poisson counts are assumed to be conditionally independent given the latent process, both over time and across categories. We consider a regression model where time-varying covariates may enter via either the Poisson model or the latent gamma process. Estimation is based on the Kalman smoother, and we consider analysis of residuals from both the Poisson model and the latent process. A reanalysis of Zeger's (1988) polio data shows that the choice between a stationary and nonstationary model is crucial for the correct assessment of the evidence of a long-term decrease in the rate of U.S. polio infection. Keywords:EM algorithm; Estimation function; Generalised linear model; Kalman filter; Kalman smoother; Latent process; Mixed Poisson distribution; Overdispersion; Regression model; Residual analysis; Time-varying covariate.

Background Omega‐3 fatty acids (n‐3 FAs) may have beneficial clinical effects, and n‐3 FA supplements may improve outcome after surgery. Methods In a randomized double‐blind placebo‐controlled trial in single centre, patients referred for elective colorectal cancer surgery received either an n‐3 FA‐enriched oral nutritional supplement (ONS) (Supportan®, 200 ml twice daily) providing 2·0 g eicosapentaenoic acid (EPA) and 1·0 g docosahexaenoic acid (DHA) per day, or a standard isocaloric and isonitrogenous ONS, for 7 days before and 7 days after surgery. The primary endpoint was infectious and non‐infectious complications within 30 days of surgery. Secondary endpoints were length of hospital stay, intensive care unit admission, readmissions, and concentrations of marine n‐3 FAs and arachidonic acid in granulocyte membranes. Results Some 148 consecutive patients (68 women, 80 men; mean age 71 (range 41–89) years) were randomized. There was no significant difference between groups in infectious or non‐infectious postoperative complications (P = 1·000). Granulocyte levels of EPA, DHA and docosapentaenoic acid (DPA) were significantly higher in the n‐3 FA‐enriched supplement group compared with the control group (P < 0·001). The arachidonic acid level in granulocytes was significantly lower in the enriched group than in the control group (P < 0·001). Conclusion EPA, DHA and DPA were incorporated into granulocytes in patients receiving n‐3 FAs, but this was not associated with improved postoperative outcomes. Registration number: NCT00488904 ( http://www.clinicaltrials.gov ).