The Norwegian Patient Registry and the Norwegian Registry for Primary Health Care: Research potential of two nationwide health-care registries.

In Norway, the Directorate of Health is responsible for two nationwide registries - the Norwegian Patient Registry (NPR) and the Norwegian Registry for Primary Health Care (NRPHC) - which together cover all governmental-funded health care. The NPR (specialist health care) was established in 2008, while the NRPHC (primary health care) was established in 2017. Data from the NPR are extensively used in a large variety of studies. We expect that data from the NRPHC will increase in importance when the registry covers a longer time period. The NRPHC will be especially important for studying conditions mainly treated in primary care and for investigation of patient trajectories. The main aim of this paper is to give an overview of the history and content of the NPR and its research possibilities. In addition, we introduce the NRPHC as a possible future research tool and the potential for studying patient trajectories when combining data from the two registries.

Age, occupational class and sickness absence during pregnancy: a retrospective analysis study of the Norwegian population registry.

OBJECTIVE: Western women increasingly delay having children to advance their career, and pregnancy is considered to be riskier among older women. In Norway, this development surprisingly coincides with increased sickness absence among young pregnant women, rather than their older counterparts. This paper tests the hypothesis that young pregnant women have a higher number of sick days because this age group includes a higher proportion of working class women, who are more prone to sickness absence. DESIGN: A zero-inflated Poisson regression was conducted on the Norwegian population registry. PARTICIPANTS: All pregnant employees giving birth in 2004-2008 were included in the study. A total number of 216 541 pregnancies were observed among 180 483 women. OUTCOME MEASURE: Number of sick days. RESULTS: Although the association between age and number of sick days was U-shaped, pregnant women in their early 20s had a higher number of sick days than those in their mid-40s. This was particularly the case for pregnant women with previous births. In this group, 20-year-olds had 12.6 more sick days than 45-year-olds; this age difference was reduced to 6.3 after control for class. Among women undergoing their first pregnancy, 20-year-olds initially had 1.2 more sick days than 45-year-olds, but control for class altered this age difference. After control for class, 45-year-old first-time pregnant women had 2.9 more sick days than 20-year-olds with corresponding characteristics. CONCLUSIONS: The negative association between age and sickness absence was partly due to younger age groups including more working class women, who were more prone to sickness absence. Young pregnant women's needs for job adjustments should not be underestimated.

Does postponement of first pregnancy increase gender differences in sickness absence? A register based analysis of Norwegian employees in 1993-2007.

BACKGROUND: From 1970-2012, the average age at first delivery increased from 23.2-28.5 in Norway. Postponement of first pregnancy increases risks of medical complications both during and after pregnancy. Sickness absence during pregnancy has over the last two decades increased considerably more than in non-pregnant women. The aim of this paper is twofold: Firstly to investigate if postponement of pregnancy is related to increased sickness absence and thus contributing to the increased gender difference in sickness absence; and secondly, to estimate how much of the increased gender difference in sickness absence that can be accounted for by increased sickness absence amongst pregnant women. METHODS: We employed registry-data to analyse sickness absence among all Norwegian employees with income equivalent to full-time work in the period 1993-2007. RESULTS: After control for age, education, and income, pregnant women's sickness absence (age 20-44) increased on average 0.94 percentage points each year, compared to 0.29 in non-pregnant women and 0.14 in men. In pregnant women aged 20-24, sickness absence during pregnancy increased by 0.96 percent points per calendar year, compared to 0.60 in age-group 30-34. Sickness absence during pregnancy accounted for 25% of the increased gender gap in sickness absence, accounting for changes in education, income and age. CONCLUSIONS: Postponement of first pregnancy does not explain the increase in pregnant women's sickness absence during the period 1993-2007 as both the highest level and increase in sickness absence is seen in the younger women. Reasons are poorly understood, but still important as it accounts for 25% of the increased gender gap in sickness absence.

A population based validation study of self-reported pensions and benefits: the Nord-Trøndelag health study (HUNT).

BACKGROUND: Measures of disability pensions, sickness certification and long-term health related benefits are often self-reported in epidemiological studies. Few studies have examined these measures, and the validity is yet to be established.We aimed to estimate the validity of self-reported disability pension, rehabilitation benefit and retirement pension and to explore the benefit status and basic characteristics of those not responding to these items.A large health survey (HUNT2) containing self-reported questionnaire data on sickness benefits and pensions was linked to a national registry of pensions and benefits, used as "gold standard" for the analysis. We investigated two main sources of bias in self-reported data; misclassification - due to participants answering questions incorrectly, and systematic missing/selection bias - when participants do not respond to the questions.Sensitivity, specificity, positive (PPV) and negative (NPV) predicative value, agreement and Cohen's Kappa were calculated for each benefit. Co-variables were compared between non-responders and responders. RESULTS: In the study-population of 40,633, 9.2% reported receiving disability pension, 1.4% rehabilitation benefits and 6.1% retirement pension. According to the registry, the corresponding numbers were 9.0%, 1.7% and 5.4%. Excluding non-responders, specificity, NPV and agreement were above 98% for all benefits. Sensitivity and PPV were lower. When including non-responders as non-receivers, specificity got higher, sensitivity dropped while the other measures changed less.Between 17.7% and 24.1% did not answer the questions on benefits. Non-responders were older and more likely to be female. They reported more anxiety, more depression, a higher number of somatic diagnoses, less physical activity and lower consumption of alcohol (p < 0.001 for all variables). For disability pension and retirement pension, non-responders were less likely to receive benefits than responders (p < 0.001). For each benefit 2.1% or less of non-responders were receivers. False positive responses were more prevalent than false negative responses. CONCLUSIONS: The validity of self-reported data on disability pension, rehabilitation benefits and retirement pension is high - it seems that participants' responses can be trusted. Compared to responders, non-responders are less likely to be receivers. If necessary, power and validity can be kept high by imputing non-responders as non-receivers.