Gastro-oesophageal reflux symptoms, oesophagitis and Barrett's oesophagus in the general population: the Loiano-Monghidoro study.

OBJECTIVE: Existing endoscopy-based data on gastro-oesophageal reflux disease (GORD) in the general population are scarce. This study aimed to evaluate typical symptoms and complications of GORD, and their associated risk factors, in a representative sample of the Italian population. METHODS: 1533 adults from two Italian villages were approached to undergo symptom assessment using a validated questionnaire and upper gastrointestinal endoscopy. Data were obtained from 1033 individuals (67.4% response rate). RESULTS: The prevalence of reflux symptoms was 44.3%; 23.7% of the population experienced such symptoms on at least 2 days per week (frequent symptoms). The prevalence rates of oesophagitis and Barrett's oesophagus in the population were 11.8% and 1.3%, respectively. Both frequent (relative risk (RR) 2.6; 95% confidence interval (CI) 1.7 to 3.9) and infrequent (RR 1.9; 95% CI 1.2 to 3.0) reflux symptoms were associated with the presence of oesophagitis. No reflux symptoms were reported by 32.8% of individuals with oesophagitis and 46.2% of those with Barrett's oesophagus. Hiatus hernia was associated with frequent reflux symptoms and oesophagitis, and was present in 76.9% of those with Barrett's oesophagus. We found no association between body mass index and reflux symptoms or oesophagitis. CONCLUSIONS: GORD is common in Italy, but the prevalence of Barrett's oesophagus in the community is lower than has been reported in selected populations. Both frequent and infrequent reflux symptoms are associated with an increased risk of oesophagitis. Individuals with oesophagitis and Barrett's oesophagus often have no reflux symptoms.

Mortality amongst participants in Vasaloppet: a classical long-distance ski race in Sweden.

OBJECTIVE: The aim of this study was to assess mortality amongst participants in long-distance ski races during the Vasaloppet week. We considered the 90 km races for men and 90 or 30 km for women. The vast majority of the participants in these races are not competing on the elite level. It is assumed, however, that they have to undergo regular physical training during a long period of time in order to successfully finish the race. DESIGN: The cohort study consisted of 49 219 men and 24 403 women, who participated in any of the races during 1989-1998. All subjects were followed up in the National-Cause-of-Death-Register until 31 December 1999. We computed the standardized mortality ratios (SMRs) adjusting for age and calendar year. RESULTS: Overall, 410 deaths occurred, compared with 850.6 expected, yielding an SMR of 0.48 [95% confidence interval (CI) 0.44-0.53]. Low SMRs were found in all age groups in both men and women and in all groups after categorization by finishing time and number of races. The lowest SMRs were found amongst older participants and in those who participated in several races. A decreased mortality was observed in all major diagnostic groups, namely cancers (SMR = 0.61; 95% CI 0.52-0.71), diseases of the circulatory system (SMR = 0.43; 95% CI 0.35-0.51), and injuries and poisoning (SMR = 0.73; 95% CI 0.60-0.89). For lung cancer the SMR was 0.22, but even after exclusion of lung cancer the all-cancer mortality was low (SMR = 0.72; 95% CI 0.59-0.86). CONCLUSIONS: We conclude that participants in long-distance skiing races, which demand prolonged regular physical training, have low mortality. The extent to which this is due to physical activity, related lifestyle factors, genetics or selection bias is yet to be assessed.

Risk of extremity fractures in adult outpatients with epilepsy.

PURPOSE: To study the incidence of extremity fractures in a group of adult patients with epilepsy attending an outpatient clinic compared with the incidence of fractures in the general population in the same geographic area. METHODS: We selected 177 consecutive adult patients with epilepsy attending the outpatient clinic at the Department of Neurology at Karolinska Hospital in Stockholm in 1995. This study population was matched with an Injury Registry to identify those epilepsy patients who during 1991 through 1995 attended the emergency department for an extremity fracture. The observed number of fractures in the epilepsy group was compared with the corresponding number of expected cases based on regional fracture rates. Relative-risk estimates for fractures were calculated with respect to the duration of epilepsy, mono- or polytherapy, and history of tonic-clonic seizures. RESULTS: Twenty (11%) of 177 patients sustained 23 fractures that prompted a visit to the emergency department. The incidence of fractures in the epilepsy patients was 23.8/1,000 person-years. The overall Standardized Morbidity Ratio (SMR) was 2.39 (95% CI, 1.52-3.59). A significantly higher risk for fractures was thus found in patients with epilepsy. Risk factors were age 45 years or older, male sex, and occurrence of generalized seizures. It also was found that the relative risk of fractures was higher during the first and second year compared with >or=5 years after diagnosis (RR, 3.71; 95% CI, 1.20-11.48). CONCLUSIONS: Our results highlight the risk of fractures in outpatients with epilepsy. In this patient group, 43% of the fractures were definitely or possibly seizure related. Males 45 years or older are a particular risk group. Special attention is required for this group of patients who are at higher risk for fractures. The risk is apparently higher in the first 2 years after diagnosis, although potential bias in ascertainment of fracture incidents in our study may have underestimated the long-term risk for fractures.

Use of low potency estrogens does not reduce the risk of hip fracture.

High endogenous sexual hormone levels and use of medium potency estrogens are associated with a reduced risk of hip fracture in postmenopausal women. However, it is not clear if low potency estrogens confer the same benefits as the more widely used forms of menopausal hormone replacement. We examined the association between postmenopausal use of low potency estrogens, mainly estriol, and hip fracture risk in a population-based, case-control study. Using data from mailed questionnaires and telephone interviews, we analyzed the association between low potency estrogen use and hip fracture risk among 1327 cases, 50-81 years of age, and 3262 randomly selected age-matched controls. Ever use of low potency estrogens was reported by 19% of the cases and 23% of controls. Compared to with never users of any hormone replacement therapy, ever users of low potency estrogens had a multivariate odds ratio (OR) for hip fracture of 0.96 (95% confidence interval [CI] 0.67-1.39). Current use was also not associated with a reduction in risk: OR 0.94 (95% CI 0.58-1.53), and longer duration of use was also not associated with a risk reduction. Even current use of the highest dose of oral estriol (2 mg/day) conferred no risk reduction (OR 1.01, 95% CI 0.61-1.67) compared with never use of hormone replacement therapy. After exclusion of ever users of medium potency estrogens from the analyses, we found a risk reduction of fracture among current vaginal low potency estrogen users (multivariate OR 0.67, 95% CI 0.49-0.92). In contrast to medium potency estrogens, low potency estrogens did not confer a substantial overall reduction in hip fracture risk.

Antiepileptic drug therapy and its management in sudden unexpected death in epilepsy: a case-control study.

PURPOSE: Because frequent seizures constitute a major risk factor for sudden unexpected death in epilepsy (SUDEP), the treatment with antiepileptic drugs (AEDs) may play a role for the occurrence of SUDEP. We used data from routine therapeutic drug monitoring (TDM) to study the association between various aspects of AED treatment and the risk of SUDEP. METHODS: A nested case-control study was based on a cohort consisting of 6,880 patients registered in the Stockholm County In Ward Care Register with a diagnosis of epilepsy. Fifty-seven SUDEP cases, and 171 controls, living epilepsy patients, were selected from the cohort. Clinical data including data on TDM were collected through medical record review. RESULTS: The relative risk (RR) of SUDEP was 3.7 (95% CI, 1.0-13.1) for outpatients who had no TDM compared with those who had one to three TDMs during the 2 years of observation. RR was 9.5 (1.4-66.0) if carbamazepine (CBZ) plasma levels at the last TDM were above and not within the common target range (20-40 microM). High CBZ levels were associated with a higher risk in patients receiving polytherapy and in those with frequent dose changes. Although the subgroup of patients with high CBZ levels was small (six cases of 33 with CBZ therapy), and the result should be interpreted with caution, no similar associations were demonstrated for phenytoin plasma levels and risk of SUDEP. No association was found between SUDEP risk and within-patient variation in AED levels over time. CONCLUSIONS: Polytherapy, frequent dose changes, and high CBZ levels as identified risk factors for SUDEP all point to the risks associated with an unstable severe epilepsy. It is unclear whether high CBZ levels per se represent a risk factor or just reflect other unidentified aspects of a severe epilepsy. Our results, however, prompt further detailed analyses of the possible role of AEDs in SUDEP in larger cohorts and suggest that reasonable monitoring of the drug therapy may be useful to reduce risks.

Influence of parity and lactation on hip fracture risk.

Several studies indicate that parity and lactation are associated with modest, short-term bone loss, but the long-term effect on osteoporotic fracture risk is uncertain. The authors therefore analyzed data from a population-based case-control study among Swedish postmenopausal women aged 50-81 years between October 1993 and February 1995. Mailed questionnaires and telephone interviews were used to collect data on 1,328 incident cases with hip fracture and 3,312 randomly selected controls. In age-adjusted analyses, the risk of hip fracture among all women was reduced by 10% per child (95% confidence interval (CI): 5, 14). After multivariate adjustment including body mass index as a covariate, the risk reduction was 5% per child (95% CI: 0, 10). Oral contraceptive use modified the association of parity with hip fracture risk. Among never users of oral contraceptives, the risk of hip fracture was reduced by 8% per child (95% CI: 2, 13), whereas among ever users of oral contraceptives, the risk was in the opposite direction, with an increase in risk by 19% per child (95% CI: 0, 41). After parity was considered, there was no association of duration of lactation period with fracture risk. The authors conclude that parity is modestly associated with a reduced hip fracture risk among women who had not used oral contraceptives previously.

Cigarette smoking, alcohol consumption, and risk of hip fracture in women.

BACKGROUND: Previous studies regarding the impact of cigarette smoking on the risk of hip fracture in postmenopausal women have been inconsistent, suggesting different effects in different groups. The effect of alcohol intake on fracture risk is puzzling: moderate alcohol intake appears to increase bone density, and its association with hip fracture is not clear. METHODS: To assess the associations of cigarette smoking and alcohol consumption with hip fracture risk among postmenopausal women, we conducted an analysis of a population-based case-control study from Sweden. Cases were postmenopausal women, aged 50 to 81 years, who sustained a hip fracture after minor trauma between October 1, 1993, and February 28, 1995; controls were randomly selected from a population-based register during the same period. A mailed questionnaire requesting information on lifestyle habits and medical history was used 3 months after the hip fracture for cases and simultaneously for controls. Age-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were computed by means of logistic regression. RESULTS: Of those eligible, 1328 cases (82.5%) and 3312 controls (81.6%) responded. Compared with never smokers, current smokers had an increased risk of hip fracture (age-adjusted OR, 1.66; 95% CI, 1.41-1.95). Duration of smoking-particularly postmenopausal smoking-was more important than the amount smoked. Former smokers had a small increase in risk (age-adjusted OR, 1.15; 95% CI, 0.97-1.37) that decreased with the duration of cessation. The age-adjusted OR for women consuming alcohol was 0.80 (95% CI, 0.69-0.93). CONCLUSIONS: Cigarette smoking is a risk factor for hip fracture among postmenopausal women; risk decreases after cessation. Alcohol consumption has a weak inverse association with risk.

Body size and hip fracture risk. Swedish Hip Fracture Study Group.

The objective of this population-based case-control study was to determine the independent association between height, weight at different ages and adult weight change on hip fracture risk, and the joint effects of these factors. The study base comprised postmenopausal women 50-81 years of age who resided in six counties in Sweden during the period October 1993 to February 1995. The study included 1,327 cases with an incident hip fracture and 3,262 randomly selected controls. We obtained information on body measures and other factors possibly related to hip fracture through mailed questionnaires and telephone interviews. Height and weight change were dominant risk factors. Tall women (> or = 169 cm) had an odds ratio of 3.16 (95% confidence interval = 2.47-4.05) compared with women shorter than 159 cm. Weight gain during adult life was strongly protective: compared with those with moderate weight change (-3 to 3 kg), those with substantial weight gain (> or =12 kg) had a markedly decreased risk of hip fracture (odds ratio = 0.35; 95% confidence interval = 0.27-0.45), whereas weight loss was associated with an increased risk. Weight change retained important effects among all subjects, even after controlling for current weight and weight at age 18. In contrast, among women who gained weight, the separate effects of current weight and weight at age 18 were small or absent. Among women who lost weight, both current weight and weight at age 18 had effects that remained after controlling for weight change. Adult weight change and height are dominant body size risk factors for hip fracture. Weight loss vs weight changes demarcates different patterns of hip fracture risk.

Physical activity and hip fracture: a population-based case-control study. Swedish Hip Fracture Study Group.

BACKGROUND: A growing body of literature suggests that physical activity may be a protective factor against hip fracture. METHODS: To study the association between hip fracture risk and recreational physical activity at various ages, changes in activity during adult life, occupational physical activity and how risks vary by adult weight change, we performed a population-based case-control study among postmenopausal women aged 50-81 years residing in six counties in Sweden in 1993-1995. The analysis consisted of 1327 women with hip fracture and 3262 randomly selected controls. Information on leisure physical activity before age 18, at 18-30 years and during recent years was based on a questionnaire. Data on occupational physical activity were collected through an independent classification of job titles obtained from record linkage with census data from 1960, 1970 and 1980. RESULTS: There was a protective effect of recent leisure physical activity. Compared to women who reported no leisure activity, the odds ratios (OR) were 0.79 (95% CI: 0.62-1.00), 0.67 (95% CI: 0.54-0.84) and 0.48 (95% CI: 0.39-0.60) for women who exercised <1 h per week, 1-2 h per week, and 3+ h per week, respectively. These decreased OR were more pronounced in women who had lost weight after 18 years of age than in those who had gained weight. Women with high physical activity at both 18-30 years and during recent years did not have a stronger protection than those with isolated high activity late in life, after accounting for recent activity. Occupational physical activity was not associated with hip fracture risk in this study. CONCLUSIONS: Recent physical activity is protective against hip fracture. The protective effect is most pronounced in women who had lost weight after age 18.

Incidence of acute myocardial infarction and cause-specific mortality after transurethral treatments of prostatic hypertrophy.

OBJECTIVES: Transurethral resection of the prostate (TURP) is associated with a higher long-term mortality than open prostatectomy which has been ascribed to a higher incidence of acute myocardial infarction (AMI). To assess the possible excess risk associated with TURP, we studied the incidence of AMI and the cause-specific mortality in patients treated with TURP and transurethral microwave thermotherapy (TUMT). METHODS: Patients treated for benign prostatic hypertrophy at a university hospital (888 patients with TURP and 478 with TUMT) were monitored during an average follow-up period of 3.9 years. The incidence of AMI and the causes of death were compared with those in the general population. RESULTS: Both treatments were followed by a higher incidence of AMI than in the general population, in particular from 2 years or more after treatment (standardized morbidity ratio 1.50, 95% confidence interval [CI] 1.14 to 1.93). The long-term mortality from all causes was increased in patients younger than 75 years of age when undergoing any of the treatments (standardized mortality ratio [SMR] 1.16, 95% CI 0.97 to 1.39), in particular, death from cardiovascular diseases (SMR 1.25, 95% CI 0.95 to 1.60) and tumors (SMR 1.54, 95% CI 1.14 to 2.03). CONCLUSIONS: The similarity of the results for TURP and TUMT suggests that the prostatic enlargement rather than the treatment is associated with cardiovascular disease.

Socioeconomic status, marital status and hip fracture risk: a population-based case-control study.

Socioeconomic status and social support have been identified as important determinants of several diseases and overall mortality, but these factors have not been adequately examined in relation to hip fracture risk. The aim of this study was to determine the relationship of socioeconomic status and marital status to hip fracture risk. We used data from a population-based case-control study in postmenopausal women aged 50-81 years during 1993-1995 who resided in six counties in Sweden. The analysis was based on 1327 incident cases of hip fracture and 3262 randomly selected controls. Socioeconomic and marital status were obtained by record linkage with census data in 1960, 1970, 1980 and 1990. Information on other possible risk factors for hip fracture was collected by a mailed questionnaire. Women who were gainfully employed in 1990 had an odds ratio (OR) of 0.74 [95% confidence interval (CI) 0.56-0.96] compared with those not gainfully employed; those in the highest tertile of household income had an OR of 0.74 (95% CI 0.60-0.90) compared with those in the lowest tertile of income. Women who lived in a one-family house had an OR of 0.85 (95% CI 0.72-0.99) compared with those living in an apartment. Divorced, widowed or unmarried women had a higher risk of hip fracture than married or cohabiting women; the OR was 1.40 (95% CI 1.06-1.85). Married women who were both gainfully employed and were living in a one-family house had a substantially decreased risk of hip fracture compared with unemployed women living without a partner in an apartment (OR 0.39; 95% CI 0.22-0.71). Occupational affiliation among women ever employed, and educational level, were not associated with hip fracture risk. We conclude that employment, household income, type of housing and marital status seem to be risk indicators of hip fracture risk independent of known osteoporotic risk factors.

Oral-contraceptive use and risk of hip fracture: a case-control study.

BACKGROUND: Epidemiological studies indicate a protective effect of postmenopausal oestrogen therapy on the risk of osteoporotic fractures. Whether premenopausal oestrogen exposure in the form of oral contraceptives also reduces the risk of osteoporotic fractures remains uncertain. METHOD: We did a population-based case control study of hip fracture among Swedish postmenopausal women, 50-81 years of age, through mailed questionnaires and telephone interviews. Of those women who were eligible, 1327 (82.5%) cases and 3312 (81.6%) randomly selected controls responded. FINDINGS: 130 (11.6%) cases and 562 (19.1%) controls reported ever-use of oral contraceptives. Ever-use of oral contraceptives was associated with a 25% reduction in hip fracture risk (odds ratio 0.75 [95% CI 0.59-0.96]). Women who had ever used a high-dose pill (equivalent to > or = 50 microg ethinylestradiol per tablet) had a 44% lower risk for hip fracture than never-users (0.56 [0.42-0.75]). No overall trend was observed with duration of oral-contraceptive use, or time since last use. However, when making comparisons with women who have never used oral contraceptives, the odds ratios for hip-fracture were 0.69 (0.51-0.94) for use after age 40, 0.82 (0.57-1.16) for use at ages 30-39, and 1.26 (0.76-2.09) for use before age 30. INTERPRETATION: Our results imply that in postmenopausal women, oral-contraceptive use late in reproductive life may reduce the risk of hip fracture, although we recognise the limitations of the case-control method.

Risk factors for sudden unexpected death in epilepsy: a case-control study.

BACKGROUND: Sudden unexpected death is substantially more common in people with epilepsy than in the general population. Our objective was to investigate the association between some clinical variables and sudden unexpected death in epilepsy (SUDEP) to identify risk factors. METHODS: This nested case-control study was based on a cohort of people aged between 15 and 70 years, who, during 1980-89, had been admitted to and discharged with a diagnosis of epilepsy from any hospital in the county of Stockholm. The study population was followed up through the National Cause of Death Register until Dec 31, 1991. Cases were individuals who had died, with a diagnosis of epilepsy registered on the death certificate, and who after review of medical and necropsy records were found to meet our SUDEP criteria. Three control participants, who were living epilepsy patients matched for age and sex, were selected from the same cohort for each case. All medical records were examined. Clinical data were collected and analysed on a predesigned protocol. FINDINGS: 57 SUDEP cases were included, of whom 91% had undergone necropsy. The relative risk of SUDEP increased with number of seizures per year. The estimated relative risk was 10.16 (95% CI 2.94-35.18) in patients with more than 50 seizures per year, compared with those with up to two seizures per year. The risk of SUDEP increased with increasing number of antiepileptic drugs taken concomitantly--9.89 (3.20-30.60) for three antiepileptic drugs compared with monotherapy. Other major risk factors were early-onset versus late-onset epilepsy (7.72 [2.13-27.96]), and frequent changes of antiepileptic drug dosage compared with unchanged dosage (6.08 [1.99-18.56]). The association between SUDEP risk and early onset, and SUDEP risk and seizure frequency, was weaker for female than for male patients, whereas frequent dose changes showed a stronger association in female patients. INTERPRETATION: Our data suggest that SUDEP is a seizure-related event, although the pathophysiological substrate that predisposes individuals to SUDEP may be established at an early age, and there may be some sex differences. Improvement of seizure control and possibly the avoidance of polytherapy may be ways to reduce the risk of SUDEP.

Differences in risk factor patterns between cervical and trochanteric hip fractures. Swedish Hip Fracture Study Group.

The two types of hip fracture--cervical and trochanteric femoral fractures--are generally considered together in etiologic studies. However, women with a trochanteric fracture may be more osteoporotic than those with cervical hip fractures, and have higher post-fracture mortality. To explore differences in risk factor patterns between the two types of hip fracture we used data from a large population-based case-control study in Swedish women, 50-81 years of age. Data were collected by questionnaire, to which more than 80% of subjects responded. Of the cases included, 811 had had a cervical fracture and 483 a trochanteric fracture during the study period; these cases were compared with 3312 randomly selected controls. Height and hormonal factors appeared to affect the risk of the two types of hip fracture differently. For every 5 cm of current height, women with a cervical fracture had an adjusted odds ratio (OR) of 1.23 (95% CI 1.15-1.32) compared with an OR of 1.06 (95% CI 0.97-1.15) for women with trochanteric fractures. Later menopausal age was protective for trochanteric fractures (OR 0.95, 95% CI 0. 91-0.99 per 2 years) but no such association was found for cervical fractures. Compared with never smokers, current smokers had an OR of 1.48 (95% CI 1.12-1.95) for trochanteric fractures and 1.22 (95% CI 0.98-1.52) for cervical fractures. Current hormone replacement therapy was similarly protective for both fracture types, but former use substantially reduced risk only for trochanteric fractures: OR 0. 55 (95% CI 0.33-0.92) compared with 1.00 (95% CI 0.71-1.39) for cervical fractures. These risk factor patterns suggest etiologic differences between the fracture types which have to be considered when planning preventive interventions.

Operative course of transurethral resection of the prostate and progression of prostate cancer.

Surgery has the potential to disseminate cancer cells, and we therefore hypothesized that extensive transurethral resections of the prostate (TURP) would be followed by a worse prognosis than minor ones. For this purpose, the association between the extent of surgery, disease progression, and mortality was studied in 138 patients with prostatic cancer who had undergone TURP. The results show that a large bleed (> or = 275 ml) indicated a slightly increased relative risk of general progression of the cancer (relative risk (RR) = 1.9, 95% confidence interval (CI) = 0.9-4.1) and death (RR = 1.5, CI = 0.6-3.3). Other parameters of extensive surgery, such as the operating time and fluid absorption, were not associated with increased risk. Patients with a medical disease, however, such as hypertension and congestive heart failure, had a significantly higher relative risk of general progression (RR = 2.7, CI = 1.2-6.1) and death from prostatic cancer (RR = 4.6, CI = 2.0-10.7) in addition to an increased relative risk of death from other causes (RR = 3.7, CI = 1.3-10.5). We conclude that concurrent medical disease, but not an extensive TURP, worsened the prognosis of patients with prostatic cancer who underwent TURP.

Hormone replacement therapy and risk of hip fracture: population based case-control study. The Swedish Hip Fracture Study Group.

OBJECTIVE: To determine the relative risk of hip fracture associated with postmenopausal hormone replacement therapy including the effect of duration and recency of treatment, the addition of progestins, route of administration, and dose. DESIGN: Population based case-control study. SETTING: Six counties in Sweden. SUBJECTS: 1327 women aged 50-81 years with hip fracture and 3262 randomly selected controls. MAIN OUTCOME MEASURE: Use of hormone replacement therapy. RESULTS: Compared with women who had never used hormone replacement therapy, current users had an odds ratio of 0.35 (95 % confidence interval 0.24 to 0.53) for hip fracture and former users had an odds ratio of 0.76 (0.57 to 1.01). For every year of therapy, the overall risk decreased by 6% (3% to 9%): 4% (1% to 8%) for regimens without progestin and 11% (6% to 16%) for those with progestin. Last use between one and five years previously, with a duration of use more than five years, was associated with an odds ratio of 0.27 (0.08 to 0.94). After five years without hormone replacement therapy the protective effect was substantially diminished (-7% to 48%). With current use, an initiation of therapy nine or more years after the menopause gave equally strong reduction in risk for hip fracture as an earlier start. Oestrogen treatment with skin patches gave similar risk estimates as oral regimens. CONCLUSIONS: Recent use of hormone replacement therapy is required for optimum fracture protection, but therapy can be started several years after the menopause. The protective effect increases with duration of use, and an oestrogen-sparing effect is achieved when progestins are included in the regimen.

Hospitalization for lower respiratory disease during 20 yrs among under 5 yr old children in Stockholm County: a population based survey.

Lower respiratory disease (LRD) is a common cause of hospitalization in infants, and episodes of obstructive LRD increase the risk for asthma later in life. The purpose of this study was to assess time trends and geographical variation of first time hospitalization for LRD among children in Stockholm County, Sweden. Data on first time admittance for LRD among children aged up to 5 yrs from 1973 through 1992 were obtained from the Stockholm County Council hospital discharge register, and population register data were used for estimation of the population at risk. Municipal data were available for 1982-1992 on outbreaks of respiratory syncytial virus (RSV) infections and socio-economic factors. A total of 12,450 children had been hospitalized for the first time with LRD. For children aged <2 yrs a 100% increase in the rate of first time hospitalization for LRD was observed during the study period and children aged up to 1 yr predominated (50%). The average yearly increase in the population based first time hospital admission rate for LRD was 1.82%. Males constituted 65% of the cases. Of the diagnoses, 89.6% were consistent with obstructive LRD, e.g. asthma and obstructive bronchitis. In children aged up to 1 yr, peaks in the rate of hospitalization tended to coincide with outbreaks of RSV infections. Differences in hospitalization between municipalities seemed to be partly explained by differences in the admission practices of the four paediatric hospitals in the area. We conclude that the increased rate of hospitalization for lower respiratory disease in infants of Stockholm County may reflect a true increase in the incidence of obstructive respiratory disease. However, several factors determine admittance to hospital and the results need to be interpreted with caution.

Blood haemoglobin and the long-term incidence of acute myocardial infarction after transurethral resection of the prostate.

OBJECTIVES: To study risk factors for acute myocardial infarction (AMI) in men suffering from benign prostatic hypertrophy. METHODS: We followed 811 patients who underwent transurethral resection of the prostate (TURP) between 1983 and 1992 until the end of 1993 with regard to the incidence of AMI. The association between AMI and various potential risk factors was evaluated by epidemiological methods. RESULTS: Fifty-two patients developed a first-time AMI after TURP. A pre-operative blood haemoglobin concentration in the range of 100-129 g/l (normal range 130-165 g/l) was associated with an increased long-term relative risk of a first-time AMI, which was estimated to be 2.0 (95% confidence interval = 1.0-4.1). This estimate became slightly stronger when we also included the 76 patients with a first AMI before surgery, 10 of whom developed a re-infarction after TURP. Furthermore, it was largely unchanged on adjusting for impaired health status and age > or = 75 years (patient factors) and for fluid absorption > or = 500 ml and a blood loss > or = 275 ml (operative factors), which had been reported to increase the long-term risk of AMI in a previous study. CONCLUSION: A moderately reduced blood haemoglobin level before TURP is associated with a doubled risk of developing AMI in later life.

Cause-specific mortality in epilepsy: a cohort study of more than 9,000 patients once hospitalized for epilepsy.

PURPOSE: We studied overall and cause-specific mortality rates in a large cohort of patients with epilepsy compared with mortality rates of the general population in the same geographic area. METHODS: The cohort consisted of all patients (N = 9,061) aged > 15 years admitted with a diagnosis of epilepsy for inpatient care in Stockholm during the years 1980-1989. All patients were followed in the National Cause-of-Death Register, from which the causes of death were obtained, until December 31, 1992. Thus, 53,520 person-years were observed. Mortality rates were compared with those of the general population of Stockholm. RESULTS: We observed 4,001 deaths in the cohort, compared with an expected number of 1,109 deaths in the general population. This yielded a standardized mortality ratio (SMR) of 3.6 [95% confidence interval (CI) 3.5-3.7]. Although highest in the younger patients, the SMR was significantly increased in all age groups. The excess mortality rate in the cohort was due to a wide range of causes of death, including malignant neoplasms [SMR 2.6 (2.4-2.8)], diseases of the circulatory system, [SMR 3.1 (3.0-3.3)], diseases of the respiratory system [SMR 4.0 (3.6-4.5)], diseases of the digestive system [SMR 5.1 (4.4-5.8)], and injuries and poisoning [SMR 5.6 (5.0-6.3)]. CONCLUSIONS: Our results demonstrate that this large subgroup of patients with a diagnosis of epilepsy, once hospitalized and discharged, is a population at risk, with an excess mortality rate due to several different causes.

The treated incidence of psychotic and affective illness in twins compared with population expectation: a study in the Swedish Twin and Psychiatric Registries.

Twin studies of psychiatric illness assume that the genetic and environmental risk factors for psychiatric illness are similar in twins and non-twins and in monozygotic (MZ) and dizygotic (DZ) twins. To test this assumption, we examine whether the treated incidence of psychiatric illness in twins deviates from population expectations or differs between MZ and DZ twins. Using first admissions to the Swedish Psychiatric Registry for the years 1979-83 for all twins born 1886-1958 from the Swedish Twin Registries, we calculated Standardized Morbidity Ratios (SMRs) using national incidence rates together with individually computed person-years at risk in the twin cohort. The diagnoses examined, for which there was more than 393000 person-years of risk, were schizophrenia, other non-affective psychoses (ONAP), bipolar affective illness (BPAI), unipolar affective illness (UPAI) and neurotic depression (ND). The SMRs (and 95% Cls) for all twins were: schizophrenia 0.86 (0.69-1.06), ONAP 1.05 (0.88-1.24), BPAI 1.09 (0.90-1.32), UPAI 1.05 (0.85-1.29) and ND 0.99 (0.88-1.10). This pattern of results did not differ substantially when examined separately by gender or birth cohort. Relative risks for first admissions for MZ v. same-sex DZ twins or same v. opposite-sex DZ twins did not differ significantly from unity for any of the disorders examined. In Sweden, the treated incidence of psychotic and affective disorders in twins does not differ from that found in the general population and does not differ across zygosity groups. These results support the validity of the twin method for the study of psychotic and affective disorders.