Methodological challenges in using the Finnish Hospital Discharge Register for studying fire-related injuries leading to inpatient care

Early Neonatal Mortality among Babies Born with Spina Bifida in Finland (2000-2014)

OBJECTIVE

 We examined early neonatal mortality risk, temporal trends, and selected infant and maternal factors associated with early neonatal mortality among all spina bifida-affected live births in Finland.

STUDY DESIGN

 We linked multiregistry population-based data from the national registers in Finland for infants born with spina bifida from 2000 to 2014. Early neonatal mortality was defined as death in 0 to 6 days after birth. Early neonatal mortality risk and 95% confidence intervals (CI) was estimated by using the Poisson approximation of binomial distribution. Poisson regression was used to examine temporal trend in early neonatal mortality from 2000 to 2014 for spina bifida cases and all births in Finland. Selected infant and maternal characteristics were compared between cases that experienced early neonatal mortality and cases that did not. Exact logistic regression was used to estimate unadjusted odds ratios (uORs) and 95% confidence intervals (CIs).

RESULTS

 A total of 181 babies were born alive with spina bifida in Finland during the study period; 61% had isolated spina bifida. Pooling all study years, 7.2% (95% CI: 4.2-12.4%) of all live-born cases experienced early neonatal death. There was a significant increase in early neonatal mortality among spina bifida births over the study period (p < 0.0001). Low gestational age (<37 weeks; uOR = 6.96; 95% CI: 1.86-29.01), cases occurring as a part of a syndrome (uOR = 125.67; 95% CI: 14.90 to >999.999), and advanced maternal age at gestation (≥35 years; uOR = 5.33; 95% CI: 1.21-21.87) were positively associated with early neonatal mortality.

CONCLUSION

 Using national data from Finland, we found high early neonatal mortality with increasing trend over birth period spanning 15 years (2000-2014), and unadjusted positive associations with some infant and maternal factors. Future studies should pool data from Nordic countries to increase study size allowing multivariable analysis.

KEY POINTS

· Early neonatal mortality in babies affected by spina bifida is 7% in Finland.. · Early neonatal mortality trend showed a significant increase from 2000 to 2014.. · Low gestational age, syndrome case status, and advanced maternal age increased early neonatal mortality risk in spina bifida..

Association between maternal pregestational diabetes mellitus and spina bifida: A population-based case-control study, Finland, 2000-2014

BACKGROUND

Maternal pregestational diabetes mellitus (PGDM) is a known risk factor for neural tube defects. We examined the association between maternal PGDM and spina bifida in the offspring using PGDM status from medical records in Finland.

METHODS

We conducted a nationally representative, multiregistry, population-based case-control study in Finland. Cases were included if they were live or stillborn infants and diagnosed with spina bifida and delivered between years 2000 and 2014 in Finland. Controls were Finnish infants without spina bifida or other major structural birth defects and delivered during the same time period as cases. Clinical and demographic data were obtained by linking multiple national health registers and census. Crude and adjusted odds ratios (ORs) and 95% confidence intervals (CI) for PGDM were estimated using logistic regression analysis. Interaction by maternal obesity was examined.

RESULTS

Our study included 181 spina bifida cases (61% isolated) and 876,672 controls. Overall, 2.2% percent of all case, and 0.5% of control mothers, had PGDM during pregnancy. Maternal PGDM was significantly associated with an increased odds of spina bifida (adjusted OR 4.35; 95% CI 1.37, 13.82). A similar association was found in our subanalysis on isolated spina bifida cases (adjusted OR 4.41; 95% CI 1.07, 18.24). There was no significant interaction by maternal obesity.

CONCLUSIONS

Maternal PGDM was positively associated with spina bifida in Finland, and maternal obesity did not modify this effect. We lacked information on maternal PGDM for electively terminated and spontaneously aborted cases; results should be interpreted with caution.

Determinants of hospitalizations for pneumonia among Finnish drug users

Objective

The study examined the determinants of being hospitalized for pneumonia in a large cohort of drug users.

Methods

Information of 4817 clients seeking treatment for illicit drug use was linked with the Finnish hospital discharge register to identify those who were hospitalized with main/primary diagnoses of pneumonia during 1997-2013. Cox regression models were used to examine the association between age, gender, homelessness, and route of drug administration of the primary drug at initial clinical consultation and pneumonia hospitalization. Findings were presented as adjusted hazard ratios and 95% confidence intervals.

Results

There were 354 persons diagnosed with pneumonia, with a total of 522 hospitalizations at the end of 2013. The univariate Cox models revealed that being over 44 years of age, male gender, homelessness, and intravenous drug use at initial clinical consultation increased the risk of being hospitalized for pneumonia. In the fully adjusted multivariate model, being over 44 years was the strongest factor independently associated with pneumonia hospitalization (adjusted hazard ratio: 2.67, 95% confidence interval: 1.56-4.57, p < 0.001), followed by homelessness (adjusted hazard ratio: 1.75, 95% confidence interval: 1.38-2.22, p < 0.001) and intravenous drug use (adjusted hazard ratio: 1.27, 95% confidence interval: 1.01-1.59, p = 0.041). Of the 354 clients hospitalized for pneumonia, 31.9% (n = 113) were rehospitalized within 30 days of being discharged. One-third of the reasons for the 30-day rehospitalization were pneumonia-related.

Conclusion

Vaccination, measures addressing housing instability, safe injecting and good hygienic practices, and treating underlying drug use problems could help to reduce morbidity for pneumonia in this cohort.

Burden of Fire Injuries in Finland: Lost Productivity and Benefits

Background: The aim of this study was to assess the economic burden of fire-related injury from two perspectives: post-injury social security compensations and also productivity losses due to the lost productive time from a societal perspective induced by the injury.

Design and methods: A cohort of 1503 inpatients who sustained fire-related injury during the period 2001–2005 was retrospectively followed up for 5-10 years until the end of 2010, using linkages between several administrative registers. The study process was started in 2015 and finalized on March 2016.

Results: Annual productivity loss was on average EUR 5.72 million, giving a total for the five-year study period of EUR 28.6 million, with a mean value of EUR 19,070 per person. Mean/median disability time for those who received benefits was 572/63 days, ranging from 3 days to 36.5 years. Total average cost of benefits to the injured annually during the study period was EUR 1.03 million. This equates to EUR 3430 per patient for the whole cohort or EUR 14,860 for those who received benefits.

Conclusions: The burden of fire-related injuries in terms of payment transfers and lost productivity due to periods of disability as indirect costs is high; in a population of 5.4 million, the annual loss exceeded EUR 5.7 million. The results could be used in planning preventive measures and therefore yield savings.

Childhood Family Income and Violent Victimization During Youth and Young Adulthood: Trends in Hospital Care During 1988-2007 in Finland

The purpose of the current study was to examine whether the relationship between childhood family income and risk of violent victimization has changed between 1988 and 2007 in Finland, as prior studies have suggested that socioeconomic differences in exposure to violence have increased during the recent decades. Existing studies have mostly relied on survey data, while such trends in hospital discharge data-a data source that covers the total population well and is not compromised by attrition or self-report bias-have not been thoroughly investigated before. The current study used register-based individual-level data from 1988-2007 (n = 283,505) to study changes in the relationship between childhood family income and victimization risk among 15- to 30-year-old Finnish men and women. We found a persisting difference in violent victimization between the top and bottom income quintiles for both men and women. While the estimates suggest that this difference has increased rather than decreased during the observation period particularly among women, this change was not statistically significant. These conclusions remain after controlling for the composition of income quintiles. Research could benefit from more extensive use of administrative hospital records in analyzing of the trends and causes of serious violence.

Factors associated with hospitalization for blood-borne viral infections among treatment-seeking illicit drug users

Blood-borne viral infections (BBVIs) are important health consequences of illicit drug use. This study assessed predictors of inpatient hospital admissions for BBVIs in a cohort of 4817 clients seeking treatment for drug use in Finland. We examined clients' data on hospital admissions registered in the Finnish National Hospital Discharge Register from 1997 to 2010 with diagnoses of BBVIs. Cox proportional hazards regression analyses were separately conducted for each of the three BBVI groups to test for association between baseline variables and hospitalizations. Findings were reported as adjusted hazard ratios (aHRs). Based upon primary discharge diagnoses, 81 clients were hospitalized for HIV, 116 for hepatitis C, and 45 for other types of hepatitis. Compared to those admitted for hepatitis C and other hepatitis, drug users with HIV had higher total number of hospital admissions (294 versus 141 and 50 respectively), higher crude hospitalization rate (7.1 versus 3.4.and 1.2 per 1000 person-years respectively), and higher total length of hospital stay (2857 days versus 279 and 308 respectively). Trends in hospitalization for all BBVI groups declined at the end of follow-up. HIV positive status at baseline (aHR: 6.58) and longer duration of drug use (aHR: 1.11) were independently associated with increased risk for HIV hospitalization. Female gender (aHR: 3.05) and intravenous use of primary drug (aHR: 2.78) were significantly associated with HCV hospitalization. Having hepatitis B negative status at baseline (aHR: 0.25) reduced the risk of other hepatitis hospitalizations. Illicit drug use coexists with blood-borne viral infections. To address this problem, clinicians treating infectious diseases need to also identify drug use in their patients and provide drug treatment information and/or referral.