Hospital Discharge Register Data Research Articles

Low temperature, cold spells, and cardiorespiratory hospital admissions in Helsinki, Finland

There is only limited scientific evidence with varying results on the association between hospital admissions and low ambient temperatures. Furthermore, there has been no research in Northern Europe on cold-associated morbidity. Therefore, this study investigated the associations of daily wintertime temperature and cold spells with cardiorespiratory hospital admissions in the Helsinki metropolitan area, Finland. Daily number of non-elective hospital admissions for 2001–2017 was obtained from the national hospital discharge register and meteorological data from the Finnish Meteorological Institute. Quasi-Poisson regression models were fitted, controlling for potential confounders such as time trend, weekday, holidays, air pollution, barometric pressure, and influenza. The associations of cold season daily mean ambient temperature and cold spells with hospital admissions were estimated using a penalized distributed lag linear models with 21 lag days. Decreased wintertime ambient temperature was associated with an increased risk of hospitalization for myocardial infarction in the whole population (relative risk [RR] per 1 °C decrease in temperature: 1.017, 95% confidence interval [CI]: 1.002–1.032). An increased risk of hospital admission for respiratory diseases (RR: 1.012, 95% CI: 1.002, 1.022) and chronic obstructive pulmonary disease (RR: 1.031, 95% CI: 1.006, 1.056) was observed only in the ≥ 75 years age group. There was an independent effect of cold spell days only for asthma admissions (RR: 2.348, 95% CI: 1.026, 5.372) in the all-ages group. Cold temperature increases the need for acute hospital care due to myocardial infarction and respiratory causes during winter in a northern climate.

Incidence and mortality of alcohol-related dementia and Wernicke-Korsakoff syndrome: A nationwide register study.

BackgroundEpidemiological data on alcohol‐related cognitive disorders are scarce. Up‐to‐date population‐based incidence and mortality rates for Wernicke‐Korsakoff syndrome (WKS) and alcohol‐related dementia (ARD) are necessary to understand the burden of these diseases.MethodsWe collected diagnostic data from the Finnish Hospital Discharge Register and mortality data from Statistics Finland for all persons aged ≥40 years who had received a diagnosis of WKS (n = 1149) or ARD (n = 2432) between 1998 and 2015 in Finland. We calculated the incidences and mortality in relation to the age‐, sex‐ and calendar year‐matched general population. Causes of death were ascertained from death certificates.ResultsFor WKS, the incidence per 100,000 person‐years (95% confidence interval (CI)) was 3.7 (3.4–3.9) in men and 1.2 (1.1–1.3) in women. For ARD, the incidence was 8.2 (7.9–8.6) in men and 2.1 (1.9–2.3) in women. The incidence of WKS peaked in people aged 50–59 years and the incidence of ARD in people aged 70–79 years. The standardized mortality ratio (95% CI) was 5.67 (5.25–6.13) in WKS patients and 5.41 (5.14–5.70) in ARD patients. Most of the excess mortality resulted from alcohol‐related causes.ConclusionsTo our knowledge, this is the first study describing population‐based incidence and mortality rates, sex‐segregated data and causes of death in patients with WKS or ARD. Our results establish a point of reference for the incidence of WKS and ARD and show the high mortality and poor prognosis of these disorders.

The Impact of the COVID-19 Pandemic on Head and Neck Cancer Diagnosis in the Piedmont Region, Italy: Interrupted Time-Series Analysis.

BackgroundThe COVID-19 pandemic has likely affected the most vulnerable groups of patients and those requiring time-critical access to healthcare services, such as patients with cancer. The aim of this study was to use time trend data to assess the impact of COVID-19 on timely diagnosis and treatment of head and neck cancer (HNC) in the Italian Piedmont region.MethodsThis study was based on two different data sources. First, regional hospital discharge register data were used to identify incident HNC in patients ≥18 years old during the period from January 1, 2015, to December 31, 2020. Interrupted time-series analysis was used to model the long-time trends in monthly incident HNC before COVID-19 while accounting for holiday-related seasonal fluctuations in the HNC admissions. Second, in a population of incident HNC patients eligible for recruitment in an ongoing clinical cohort study (HEADSpAcE) that started before the COVID-19 pandemic, we compared the distribution of early-stage and late-stage diagnoses between the pre-COVID-19 and the COVID-19 period.ResultsThere were 4,811 incident HNC admissions in the 5-year period before the COVID-19 outbreak and 832 admissions in 2020, of which 689 occurred after the COVID-19 outbreak in Italy. An initial reduction of 28% in admissions during the first wave of the COVID-19 pandemic (RR 0.72, 95% CI 0.62–0.84) was largely addressed by the end of 2020 (RR 0.96, 95% CI 0.89–1.03) when considering the whole population, although there were some heterogeneities. The gap between observed and expected admissions was particularly evident and had not completely recovered by the end of the year in older (≥75 years) patients (RR: 0.88, 0.76–1.01), patients with a Romano-Charlson comorbidity index below 2 (RR 0.91, 95% CI: 0.84–1.00), and primary surgically treated patients (RR 0.88, 95% CI 0.80–0.97). In the subgroup of patients eligible for the ongoing active recruitment, we observed no evidence of a shift toward a more advanced stage at diagnosis in the periods following the first pandemic wave.ConclusionsThe COVID-19 pandemic has affected differentially the management of certain groups of incident HNC patients, with more pronounced impact on older patients, those treated primarily surgically, and those with less comorbidities. The missed and delayed diagnoses may translate into worser oncological outcomes in these patients.

Change in medical practice over time? A register based study of regional trends in hysterectomy in Finland in 2001\u20132018

BackgroundA persistent research finding in Finland and elsewhere has been variation in medical practices both between and within countries. Variation seems to exist especially if medical decision making involves discretion and the best treatment cannot be identified unambiguously. This is true for hysterectomy when performed for benign causes. The aim of the current study was to investigate regional trends in hysterectomy in Finland and the potential convergence of rates over time.MethodsWe used hospital discharge register data on hysterectomies performed, diagnoses, age, and region of residence to examine hospital discharges for women undergoing hysterectomy in 2001–2018 among total female population aged 25 years or older in Finland. We examined hysterectomy rates among biannual cohorts by indication, calculated age-standardised rates and used multilevel models to analyse potential convergence over time.ResultsAltogether 131,695 hysterectomies were performed in Finland 2001–2018. We found a decreasing trend, with the age-adjusted overall hysterectomy rate decreasing from 553/100,000 person years in 2001–2002 to 289/100,000 py in 2017–2018. Large but converging regional differences were found. The correlations between hospital district intercepts and slopes in time ranged from − 0.71 to − 0.97 (p < 0.001) suggesting diminishing variation.ConclusionsOur findings demonstrate that change in hysterectomy practices and more uniformity across regions are achievable goals. Regional variation still exists suggesting differences in medical practices.

Regional variation in appropriate care for ST-elevation myocardial infarction in Finland

Abstract Background Timely primary percutaneous coronary intervention (PCI) is currently the treatment of choice for ST-elevation myocardial infarction (STEMI). Although cardiac units were established in all central hospitals in late 1990s for sparsely populated Finland, studies have shown that regional variation has increased. Additionally, the dense Finnish hospital network includes non-cardiac facilities where patients may be inappropriately admitted and then transferred for PCI. We aim to investigate the current regional differences in receiving timely PCI, determinants of these variations and the effect of hospital transfers. Methods Finnish Hospital Discharge Register data on PCIs for STEMI patients in 2015-17 were linked to register data on socio-demographics. In these preliminary analyses we used logistic regression modelling. Results Our results suggest that there were significant regional differences both for timely PCI in STEMI patients and in the probability of hospital transfers during an episode of care. The regional odds ratios (OR) for receiving PCI on time varied from 0.41 (95% confidence interval 0.33-0.52) to 2.73 (2.09-3.57) compared with the capital region when controlling for age, gender and hospital transfers. The ORs for being transferred during an episode of care varied from 0.26 (0.15-0.44) to 16.6 (11.6-23.6). Patients not transferred were more likely to receive PCI (OR 1.89 (1.67-2.15)). Men received PCI on time more often (OR 1.31 (1.18-1.46)) and women were more likely to be transferred (OR 1.29 (1.15-1.45)). Conclusions The probability for receiving PCI on time was related to the size of the hospital's population base and academic affiliation and inversely to transfers between hospitals. Hospital transfers during care episode and atypical symptoms often seen in women may cause critical delays for PCI. Other determinants for variation of timely PCI and its effects on equity will be analysed using multilevel modelling. Key messages Appropriate care for STEMI varies across regions and reflects inept practices in provider network. These findings are more pronounced in women showing persisting gender-related inequity.

The association between bacterial infections and the risk of coronary heart disease in type 1 diabetes.

Diabetes increases the risk of infections and coronary heart disease (CHD). Whether infections increase the risk of CHD and how this applies to individuals with diabetes is unclear. To investigate the association between bacterial infections and the risk of CHD in type 1 diabetes. Individuals with type 1 diabetes (n=3781) were recruited from the Finnish Diabetic Nephropathy Study (FinnDiane), a prospective follow-up study. CHD was defined as incident events: fatal or nonfatal myocardial infarction, coronary artery bypass surgery or percutaneous coronary intervention, identified through national hospital discharge register data. Infections were identified through national register data on all antibiotic purchases from outpatient care. Register data were available from 1 January 1995 to 31 December 2015. Bacterial lipopolysaccharide (LPS) activity was measured from serum samples at baseline. Data on traditional risk factors for CHD were collected during baseline and consecutive visits. Individuals with an incident CHD event (n=370) had a higher mean number of antibiotic purchases per follow-up year compared to those without incident CHD (1.34 [95% CI: 1.16-1.52], versus 0.79 [0.76-0.82], P<0.001), as well as higher levels of LPS activity (0.64 [0.60-0.67], versus 0.58EUmL-1 [0.57-0.59], P<0.001). In multivariable-adjusted Cox proportional hazards models, the mean number of antibiotic purchases per follow-up year was an independent risk factor for incident CHD (HR 1.21, 95% CI: 1.14-1.29, P<0.0001). High LPS activity was a risk factor for incident CHD (HR 1.93 [1.34-2.78], P<0.001) after adjusting for static confounders. Bacterial infections are associated with an increased risk of incident CHD in individuals with type 1 diabetes.

The validity of hospital discharge register data on non-ST-elevation and ST-elevation myocardial infarction in Finland

Objectives. To examine the validity of ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI) diagnoses in Finnish nation-wide hospital discharge register (HDR). Design. In the first stage of the study, we sampled 180 patients treated in 1996–2012 for MI in three different hospitals, Oulu university hospital, Turku university hospital and North Karelia Central hospital, 60 patients in each hospital. A cardiology resident classified the patients on the basis of ECG finding into following categories: NSTEMI, STEMI or not classifiable myocardial infarction (NCMI). In the second stage of the study, we sampled altogether 270 additional patients i.e. 90 patients per hospital. Patients were treated between 2012-2014 for STEMI (n = 3 × 30), NSTEMI (n = 3 × 30), and NCMI (n = 3 × 30). The ECGs of these patients were independently evaluated by the cardiology resident and a senior cardiologist and compared with the HDR diagnosis. Results. In the first stage of the study, the agreement between the ECG coding of the cardiology resident and the HDR diagnoses was poor (Cohen’s kappa coefficient 0.38 (95% CI 0.10–0.32). In the second stage, the agreement remained at the same poor level (Cohen’s kappa = 0.22 (95% CI 0.11–0.03)). The agreement between the cardiology resident and the senior cardiologist was, however, good (Cohen’s kappa = 0.75 (95% CI 0.65–0.85)). Conclusions. Our results show that the division of MI diagnoses to STEMI and NSTEMI is not reliable in the Finnish HDR. These diagnoses should not be used as outcomes in scientific research without additional verification from the original ECGs.

Maternal Smoking and Hospital Treatment During Pregnancy.

Previous research suggests that young maternal age, smoking, hospitalization during a previous pregnancy, and poor self-rated health could be risk factors for prenatal hospitalization. The objective of this retrospective observational register study was to investigate if maternal smoking during pregnancy is associated with mother's need for hospital treatment during pregnancy. The study population consists of all singleton pregnancies (n = 961 127) in 1999-2015 in Finland. Information on maternal smoking was received from the Medical Birth Register in three classes: nonsmoker, quit smoking in the first trimester, and continued smoking throughout the pregnancy. These data were linked with the Hospital Discharge Register data and analyzed according to ICD-10 chapters. 10.7% of women continued to smoke after the first trimester. After adjusting for confounding factors women in both smoking groups had more hospital treatment compared with nonsmokers. Especially outpatient treatment was more common among mothers who continued to smoke compared to those who quit smoking in the first trimester in several ICD-10 chapters. Compared to non-smokers, aOR for mental and behavioral disorders (F00-F99) was 2.14 (95% confidence interval 2.00-2.30) in the quit smoking group and 3.88 (3.71-4.06) in the continued smoking group. Similarly, aOR for respiratory diseases (J00-J99) was 1.26 (1.15-1.39) and 1.61 (1.52-1.71), respectively and aOR for genitourinary diseases (N00-N99) was 1.10 (1.03-1.17) and 1.29 (1.23-1.35), respectively. Some similar findings were made also in inpatient care. Some similar findings were made also in inpatient care. Women who smoke during pregnancy seem to require more hospital care for various reasons. These findings emphasize the importance of actions for smoking cessation during pregnancy and women should be encouraged to quit as early as possible. Maternal smoking during pregnancy is associated with greater rates of both outpatient and inpatient hospital care during pregnancy. Women who quit smoking had a similar risk for hospital care during pregnancy with nonsmokers in certain diagnosis chapters, which is very motivational and could be used as an informational tool in prenatal clinics to encourage smoking cessation as it is never too late to quit smoking during pregnancy.

The incidence of paediatric ACL injury is increasing in Finland

PurposeAnterior cruciate ligament (ACL) injury is a common knee injury in paediatric and adolescent patients. The population-based incidence of paediatric ACL injury is, however, unknown. Recent studies suggest increased ACL injury rates among adolescents, especially in active, sports-participating population. The purpose of this study was to investigate the population-based incidence rates of ACL injuries and trends in paediatric ACL reconstruction surgery.MethodAll ACL injuries were identified (ICD-10 diagnosis code S83.5) leading to hospitalisation or surgery using validated Finnish National Hospital Discharge Register (NHDR) data from 1997 to 2014. The sample comprised 19,961,205 Finnish residents aged less than 18 years at the time of injury. Hospital admissions with the diagnosis code S83.5 were analysed more thoroughly including, sex, age and the need for surgical interventions.ResultsDuring the 18-year study period, 4725 subjects of the study population had sustained an ACL injury. The total ACL injury incidence in study population was 23.3 per 100,000 person-years. The median age of the patients at the time of injury was 16 years (range 4–17). The incidence of ACL injury increased with age, and the highest incidence was observed among 17-year old (113.5 per 100,000 person-years). Incidence rate did not differ between genders. From the total ACL injury population of 4725 hospitalisations, 3168 (67.0%) underwent ACL reconstruction, of which 2988 (94.3%) were treated with arthroscopic reconstruction and 180 (5.6%) with open surgery. In addition, 1557 (33.0%) were treated non-operatively without ACL reconstruction. The annual incidence of ACL injuries in the Finnish paediatric population has increased during the past 15 years. The lowest incidence rate was seen in 1999 (incidence of 17.7 per 100,000 person-years, 195 ACL injuries) and the highest in 2011 (incidence of 31.5 per 100,000 person-years, 346 ACL injuries). The highest increase in ACL injuries was seen in girls aged 13–15 years, with an increase of 143%.ConclusionACL injury is not a negligible knee injury in the paediatric population. The incidence of paediatric ACL injury has increased during the past 15 years. Moreover, a twofold increase in incidence of paediatric ACL injury was noted during the last 10 years of the study period. Incidence rates among male and female paediatric patients were comparable.Level of evidenceIII.

The validity of heart failure diagnoses in the Finnish Hospital Discharge Register

Background: Contemporary validation studies of register-based heart failure diagnoses based on current guidelines and complete clinical data are lacking in Finland and internationally. Our objective was to assess the positive and negative predictive values of heart failure diagnoses in a nationwide hospital discharge register. Methods: Using Finnish Hospital Discharge Register data from 2013-2015, we obtained the medical records for 120 patients with a register-based diagnosis for heart failure (cases) and for 120 patients with a predisposing condition for heart failure, but without a heart failure diagnosis (controls). The medical records of all patients were assessed by a physician who categorized each individual as having heart failure (with reduced or preserved ejection fraction) or no heart failure, based on the definition of current European Society of Cardiology heart failure guidelines. Unclear cases were assessed by a panel of three physicians. This classification was considered as the clinical gold standard, against which the registers were assessed. Results: Register-based heart failure diagnoses had a positive predictive value of 0.85 (95% CI 0.77-0.91) and a negative predictive value of 0.83 (95% CI 0.75-0.90). The positive predictive value decreased when we classified patients with transient heart failure (duration <6 months), dialysis/lung disease or heart failure with preserved ejection fraction as not having heart failure. Conclusions: Heart failure diagnoses of the Finnish Hospital Discharge Register have good positive predictive value and negative predictive value, even when patients with pre-existing heart conditions are used as healthy controls. Our results suggest that heart failure diagnoses based on register data can be reliably used for research purposes.

Lifestyle Risk Factors Increase the Risk of Hospitalization for Sciatica: Findings of Four Prospective Cohort Studies

BackgroundThe purpose of this study is to assess the effects of lifestyle risk factors on the risk of hospitalization for sciatica and to determine whether overweight or obesity modifies the effect of leisure-time physical activity on hospitalization for sciatica. MethodsWe included 4 Finnish prospective cohort studies (Health 2000 Survey, Mobile Clinic Survey, Helsinki Health Study, and Young Finns Study) consisting of 34,589 participants and 1259 hospitalizations for sciatica during 12 to 30 years of follow-up. Sciatica was based on hospital discharge register data. We conducted a random-effects individual participant data meta-analysis. ResultsAfter adjustment for confounding factors, current smoking at baseline increased the risk of subsequent hospitalization for sciatica by 33% (95% confidence interval [CI], 13%-56%), whereas past smokers were no longer at increased risk. Obesity defined by body mass index increased the risk of hospitalization for sciatica by 36% (95% CI 7%-74%), and abdominal obesity defined by waist circumference increased the risk by 41% (95% CI 3%-93%). Walking or cycling to work reduced the risk of hospitalization for sciatica by 33% (95% CI 4%-53%), and the effect was independent of body weight and other leisure activities, while other types of leisure activities did not have a statistically significant effect. ConclusionsSmoking and obesity increase the risk of hospitalization for sciatica, whereas walking or cycling to work protects against hospitalization for sciatica. Walking and cycling can be recommended for the prevention of sciatica in the general population.

Sibling risk of hospitalization for heart failure – A nationwide study

BackgroundThe familial risks of heart failure (HF) remain largely undetermined. This nationwide follow-up study aimed at determining risk of hospitalization for HF conferred by affected siblings. Methods and resultsSwedish Multi-generation Register data, with records of at least one full sibling available at start of follow-up, were linked to the Hospital Discharge Register data for 1987–2010. The oldest participants were aged 78years in 2010. Relative risks, standardized incidence ratios (SIRs), of HF hospitalization were calculated for individuals with siblings hospitalized with HF compared with those whose siblings were not. Adjustments were made for common HF comorbidities, age, time period, socioeconomic status and region.During the 24year follow-up (1987–2010) 23,212 individuals (7155 females), were hospitalized because of HF. From this total, 1121 had at least one full sibling hospitalized for HF. Sibling risks were generally similar for males and females. The SIR of HF hospitalization was 1.62 (95% confidence interval 1.54–1.70) for individuals with one affected sibling and 15.46 (12.82–18.50) for individuals with two affected siblings.The SIR conferred by one or more affected siblings was 2.67 (2.24–3.16) below the age of 50years, 1.92 (1.75–2.10) between 50 and 59years of age, 1.63 (1.52–1.76) between 60 and 69years of age, and 1.54 (1.38–1.71) between 70 and 78years of age. Spouses had low familial risks: SIR=1.04 (1.03–1.06). ConclusionsFamilial factors are important risk factors in HF, with particularly high risks among individuals with two or more affected siblings and in early onset of HF.

Parental poverty and occupation as risk factors for pediatric sleep-disordered breathing

Objectives/BackgroundPrevious studies have found associations between pediatric sleep-disordered breathing (SDB) and socioeconomic status (SES), as well as a neighborhood-related disadvantage. This study analyzes the association among familial SES, parental occupation, and SDB in Swedish offspring. MethodsA nationwide dataset was constructed by linking Swedish census data to hospital discharge register data on all first hospitalizations of children and adolescents aged 0–18 years during the study period 1997–2007. The outcome was SDB, defined as diagnostic codes for obstructive sleep apnea (OSA), adenotonsillar hypertrophy, or tonsillar hypertrophy. Familial SES was defined as family income and maternal education. The odds ratio (OR) was calculated with a 95% confidence interval (CI). Results34,933 of three million children had a first hospital diagnosis of SDB. The OR was significantly increased in offspring in families with a low income (1.79) and maternal education (1.21). Significantly increased ORs were found in 14 of 38 maternal (37%) and 13 of 48 paternal (27%) occupations, and six of them involved both parents: drivers, welders, and workers in mechanics and iron metalware, chemical processing, and manufacture of food and glass. A significantly decreased OR was found in 12 (25%) of the paternal occupations, e.g., scientists, physicians, teachers, artists, administrators, and farmers, as well as in maternal occupations, such as artists and farmers, with offspring aged 0–6 years. ConclusionThis study indicates that low familial SES and parental occupations associated with a low educational level increased, whereas academic parental occupations and farmers decreased the risk of SDB in offspring.

O-205 Parental Cardiovascular Morbidity In Families With A Preterm Child, A National Register Study

Background Prematurity is associated with a higher incidence of hypertension and glucose metabolism during childhood and young adulthood. This may be due to circumstances during fetal and early postnatal life or to confounders such as unhealthy lifestyle in childhood home. The confounder explanation would gain support if preterm birth would predict father’s cardiovascular disease (CVD). Objective We hypothesised that preterm birth would predict cardiovascular disease in both parents. Design/methods Pregnancy data came from Finnish Medical Birth Register. During Jan 1, 1987 and Sep 30, 1990, we included the first singleton birth for each of the 196,427 mothers. National Population Register Centre tracked the fathers, 3,048 remained missing (and 27 mothers). We obtained Hospital Discharge Register data from Aug, 1969, and non-primary care out-patient visit data from Sep 1986, both until 31 Dec 2012. The first occasion of CVD was when the ICD-9 and ICD-10 indicated coronary heart disease (CHD) or stroke. We utilised Cox regression for proportional hazards to analyse the effect of GA group on CVD in mothers and fathers separately. Results In mothers, preterm birth predicted CVD with Hazard Ratios (HRs) increasing up to 2.12 with shorter gestation ( Table 1 ). Among thefathers, those whose baby had been born preterm were clearly not at ahigher risk for a CVD diagnosis ( Table 2 ). Conclusions Since preterm birth predicted CVD only in mothers and not fathers, the higher CVD risk factors in those born preterm are unlikely to be mediated by unhealthy habits learnt from the parents.

P021: The validity of national hospital discharge register data on dementia; a comparative analysis using data from a university medical center

P021: The validity of national hospital discharge register data on dementia; a comparative analysis using data from a university medical center

Family history of venous thromboembolism (VTE) and risk of recurrent hospitalization for VTE: a nationwide family study in Sweden

Data concerning the importance of a family history of venous thromboembolism (VTE) for the risk of recurrent VTE are sparse. The aim of this nationwide study was to determine whether a family history of VTE is a risk factor for recurrent hospitalization for unprovoked VTE (deep vein thrombosis of the lower extremities or pulmonary embolism). We linked Multigeneration Register data on individuals aged 0-77years to the Swedish nationwide Hospital Discharge Register data for the period 1987-2009 to compare the risk of hospitalization for unprovoked recurrent VTE among individuals with and without a parental or sibling history of VTE. We calculated hazard ratios (HRs) to determine the familial HR for recurrent hospitalization for VTE. The risk of recurrent VTE hospitalization was 1.20 (95% confidence interval [CI]1.10-1.32) for individuals with affected parents, and 1.30 (95%CI1.14-1.49) for those with affected siblings. The risk of recurrent VTE hospitalization in individuals with two affected parents was 1.92 (95%CI1.44-2.58). There was an interaction between age at diagnosis of VTE and a family history of VTE, with a family history having a stronger effect on VTE risk in younger patients. We conclude that a family history of VTE is a modest risk factor for recurrent VTE hospitalization in Sweden.

Family history as a predictor of hospitalization for hypertension in Sweden

Hypertension clusters in families. However, no nationwide study has investigated the family history as a predictor of hospitalization for hypertension, which was the purpose of this study. The study is a nationwide follow-up study. Swedish Multigeneration Register data for individuals aged 0-76 years were linked to Hospital Discharge Register data for 1964-2008. Standardized incidence ratios (SIRs) were calculated for individuals whose relatives were hospitalized with a main diagnosis of hypertension compared with those whose relatives were not. The total number of patients hospitalized with hypertension was 37,686. The familial SIR was 2.18 for individuals with one affected sibling, 44.83 for individuals with two affected siblings and 57.18 for individuals with three or more affected siblings. The SIR was 1.95 for parents with one affected child, 3.73 for parents with two affected children and 9.22 for parents with three or more affected children. The familial SIR among offspring was 1.84 for those with one affected parent and 3.62 for those with two affected parents. The familial risk for hospitalization with hypertension among offspring aged less than 30 years was 2.50 and 1.57 in those aged more than 60 years. Familial risks were similar for men and women. Spouses had low overall familial risks (SIR=1.2). Hospitalization for hypertension clusters in families. Very high risks were observed in families with multiple affected siblings, though the parent-offspring transmission was lower, suggesting the segregation of recessive or interacting susceptibility genes. The low familial risk in spouses suggests a minor nongenetic contribution.

Loop Electrosurgical Excision Procedure and the Risk for Preterm Delivery

To estimate whether the severity of cervical intraepithelial neoplasia (CIN) and the loop electrosurgical excision procedure (LEEP) increase the risk for preterm delivery, and to evaluate the role of repeat LEEP and time interval since LEEP. This was a retrospective register-based study from Finland from 1997 to 2009. We linked Hospital Discharge Register and Finnish Medical Birth Register data. Case group women consisted of 20,011 women who underwent LEEP during the study period and their subsequent singleton deliveries in 1998-2009. Control population included women from the Medical Birth Register with no LEEP (n=430,975). The main outcome measure was preterm delivery before 37 weeks of gestation. The risk for preterm delivery increased after LEEP. Women with previous LEEP had 547 (7.2%) preterm deliveries, whereas the control population had 30,151 (4.6%) preterm deliveries (odds ratio [OR] 1.61, confidence interval [CI] 1.47-1.75, number needed to harm 38.5). The overall preterm delivery rate in the study period was 4.6% for singleton deliveries. Repeat LEEP was associated with an almost threefold risk for preterm delivery (OR 2.80, CI 2.28-3.44). The severity of CIN did not increase the risk for preterm delivery. However, with LEEP for carcinoma in situ or microinvasive cancer, the risk for preterm delivery was higher (OR 2.55, CI 1.68-3.87). The increased risk also was associated with non-CIN lesions (OR 2.04, CI 1.46-2.87). Similarly, the risk was increased after diagnostic LEEP (OR 1.39, 95% CI 1.16-1.67). Time interval since LEEP was not associated with preterm delivery. Adjusting for maternal age, parity, socioeconomic or marital status, urbanism, and previous preterm deliveries did not change the results. The risk for preterm delivery was increased after LEEP regardless of the histopathologic diagnosis. The risk was highest after repeat LEEP, which should be avoided, especially among women of reproductive age. II.

Shared and non-shared familial susceptibility of coronary heart disease, ischemic stroke, peripheral artery disease and aortic disease

Little is known about whether the four main manifestations of arterial vascular disease (coronary heart disease = CHD, ischemic stroke, peripheral artery disease = PAD, and aortic (i.e. atherosclerosis/aneurysm) disease = AD) share familial susceptibility. The aim of this nationwide study was to determine the familial risks of concordant (same disease in proband and exposed relative) and discordant (different disease in proband and exposed relative) cardiovascular disease (CVD). Data from the Swedish Multigeneration Register on individuals aged 0-76 years were linked to Swedish Hospital Discharge Register data for the period 1964-2008. Standardized incidence ratios (SIRs) for CHD (n = 140,708 cases), ischemic stroke (n = 73,771), PAD (n = 18,982) and AD (n = 7879) were calculated for siblings of individuals hospitalized due to CHD, stroke, PAD or AD compared to those of unaffected siblings. The procedure was repeated for parent-offspring and spouses. All concordant and discordant sibling risks were increased for both males and females. Concordant risks were generally higher than discordant risks. The highest sibling risks were observed for premature concordant disease (<55 years for males and <65 years for females): SIR for CHD = 1.93 (95% CI: 1.90-1.96), SIR for ischemic stroke = 1.45 (1.39-1.50), SIR for PAD = 2.76 (2.54-3.00), and SIR for AD = 6.36 (5.28-7.59). Premature parent-offspring transmission followed the same pattern. The disease risk was modestly increased in spouses, highest for AD (SIR = 1.48 (1.28-1.69)) and PAD (SIR = 1.27 (1.21-1.32)). The four main manifestations of CVD share familial susceptibility, but unique site-specific familial factors may exist.

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

BackgroundThe objective was to examine feasibility of using hospital discharge register data for studying fire-related injuries.MethodsThe Finnish National Hospital Discharge Register (FHDR) was the database used to select relevant hospital discharge data to study usability and data quality issues. Patterns of E-coding were assessed, as well as prominent challenges in defining the incidence of injuries. Additionally, the issue of defining the relevant amount of hospital days accounted for in injury care was considered.ResultsDirectly after the introduction of the ICD-10 classification system, in 1996, the completeness of E-coding was found to be poor, but to have improved dramatically around 2000 and thereafter. The scale of the challenges to defining the incidence of injuries was found to be manageable. In counting the relevant hospital days, psychiatric and long-term care were found to be the obvious and possible sources of overestimation.ConclusionsThe FHDR was found to be a feasible data source for studying fire-related injuries so long as potential challenges are acknowledged and taken into account. Hospital discharge data can be a unique and powerful means for injury research as issues of representativeness and coverage of traditional probability samples can frequently be completely avoided.