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.

Alcohol consumption, Type 2 diabetes mellitus and impaired glucose tolerance in middle-aged Swedish men.

AIMS: To investigate the association between alcohol consumption and impaired glucose tolerance and Type 2 diabetes mellitus. METHODS: A population-based cross-sectional study consisting of 3,128 Swedish men, aged 35-56 years. Oral glucose tolerance testing identified 55 cases of Type 2 diabetes and 172 cases of impaired glucose tolerance. Information on alcohol consumption, family history of diabetes, smoking and physical activity was obtained by questionnaire. RESULTS: After adjustment for family history, smoking, physical activity and body mass index, the odds ratio of diabetes was 2.1 (95% confidence interval (CI) 1.0-4.5) in men with high consumption of alcohol (corresponding to over 12 drinks per week) and 0.7 (0.3-1.8) in moderate consumers (7-12 drinks), compared to occasional drinkers. For impaired glucose tolerance, the corresponding odds ratios were 0.7 (0.5-1.1) and 0.6 (0.4-1.0), respectively. Separate analyses for type of beverage indicated that high consumers of beer, spirits and wine had an odds ratio for diabetes of 2.9 (1.2-6.9), 3.3 (1.4-7.8) and 1.2 (0.5-2.7), respectively. CONCLUSIONS: The results indicated that high consumption of alcohol increases the occurrence of Type 2 diabetes and that this may primarily concern consumption of beer and spirits. For impaired glucose tolerance, regular alcohol consumption was associated with a reduced prevalence, particularly at moderate levels.

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.

Cigarette smoking, oral moist snuff use and glucose intolerance.

OBJECTIVE: To investigate the association between cigarette smoking and use of oral moist snuff and impaired glucose tolerance and type 2 diabetes. DESIGN: We performed a population-based cross-sectional study of glucose intolerance and tobacco use in Stockholm during 1992-94. The sample consisted of 3128 men, aged 35-56 years, of whom 52% had a family history of diabetes. In an oral glucose tolerance test, we detected 55 men with type 2 diabetes and 172 with impaired glucose tolerance. Information on cigarette smoking and oral moist snuff use was collected by a questionnaire. RESULTS: The odds ratio of type 2 diabetes was increased for smokers of 25+ cigarettes day-1 (odds ratio = 2.6, 95% confidence interval = 1.1-5.9) as well as for moist snuff dippers of 3+ boxes week-1 (odds ratio = 2.7, 95% confidence interval = 1.3-5.5). The odds ratio of relatively high (highest tertile) fasting insulin levels in subjects with impaired glucose tolerance associated with cigarette smoking of 25+ cigarettes day-1 was 1.5 (95% confidence interval = 0.7-3.6). The corresponding estimate of a relatively low (lowest tertile) 2 h insulin response was 2.5 (95% confidence interval = 0.9-7.1). CONCLUSIONS: These results indicate that heavy users of cigarettes or moist snuff have an increased risk of type 2 diabetes. The results could suggest that tobacco use is associated with a low insulin response.

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.

Low birth weight, family history of diabetes, and glucose intolerance in Swedish middle-aged men.

OBJECTIVE: To investigate the association between low birth weight and glucose intolerance in relation to family history of diabetes. RESEARCH DESIGN AND METHODS: We conducted a population-based cross-sectional study of 2,237 men born in 1938-1957 in four municipalities in the outskirts of Stockholm, 50% of whom had a family history of diabetes (at least one first-degree or two second-degree relatives with diabetes). Oral glucose tolerance testing detected 35 cases of type 2 diabetes, 102 cases of impaired glucose tolerance, and 57 cases of impaired fasting glucose. RESULTS: In subjects without a family history of diabetes, low (< or = 3,000 g) birth weight was associated with an odds ratio of 2.3 (95% confidence intervals = 0.4-14.4) for diabetes, 1.8 (0.7-4.3) for impaired glucose tolerance, and 3.3 (1.0-10.4) for impaired fasting glucose. In subjects with a family history of diabetes, the corresponding figures were approximately similar, except for diabetes, for which the odds ratio was 5.4 (2.0-14.9). For men with low birth weight in combination with a family history of diabetes, the odds ratio was 10.9 (2.9-41.2) for diabetes, 2.4 (1.1-5.6) for impaired glucose tolerance, and 5.9 (2.1-16.3) for impaired fasting glucose. CONCLUSIONS: This study indicated that low birth weight is associated with type 2 diabetes, impaired glucose tolerance, and impaired fasting glucose in men. This finding was most pronounced in subjects with diabetes in the family, but it was also indicated in those without a family history of diabetes. Men with the combination of low birth weight and family history of diabetes seem to be at particularly high risk of developing type 2 diabetes.

Increased risk of cancer in ulcerative colitis: a population-based cohort study.

OBJECTIVE: There is an increased risk of colorectal cancer among patients with ulcerative colitis (UC). However, the overall and site specific cancer risks in these patients have been investigated to a limited extent. To study the association between UC and cancer, a population-based study of 1547 patients with UC in Stockholm diagnosed between 1955 and 1984 was carried out. METHODS: The patients were followed in both the National Cancer Register and the National Cause of Death Register until 1989. For comparisons, regional cancer incidence rates in Stockholm County were used together with individually computed person-years at risk in the UC disease cohort. RESULTS: A total of 121 malignancies occurred among 97 individuals as compared with 89.8 expected (standardized morbidity ratio [SMR] = 1.4; 95% confidence interval (CI), 1.1-1.6). Overall, an excess number of colorectal cancers (SMR, 4.1; 95% CI, 2.7-5.8), and hepatobiliary cancers in men (SMR = 6.0; 95% CI, 2.8-11.1) associated with primary sclerosing cholangitis, was observed. The risk of pulmonary cancer was decreased (SMR = 0.3; 95% CI, 0.1-0.9). In all, 91 extracolonic malignancies were observed, compared with the 82.3 expected (SMR = 1.11; 95% CI, 0.9-1.3). CONCLUSIONS: In UC patients, the overall cancer incidence is increased mainly because of an increased incidence of colorectal and hepatobiliary cancer. This increase is partly counterbalanced by a decreased risk of pulmonary cancer compared with that in the general population.

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.

Weight history, glucose intolerance, and insulin levels in middle-aged Swedish men.

The association between weight history and glucose intolerance was examined in a cross-sectional study consisting of 3,128 Swedish men aged 35-56 years, 52 percent of whom had a family background of diabetes mellitus. Oral glucose tolerance testing detected 55 cases of type 2 (non-insulin-dependent) diabetes and 172 cases of impaired glucose tolerance. Among men with no family history of diabetes, the estimated odds ratios for impaired glucose tolerance associated with short (<5 years) and long (> or =10 years) durations of obesity (body mass index (weight (kg)/height2 (m2) > or =25.0) were 1.3 (95% confidence interval (CI) 0.2-7.7) and 11.8 (95% CI 3.3-41.9), respectively. Among men with a family history of diabetes, the odds ratios were 2.0 (95% CI 0.8-4.7) and 4.0 (95% CI 1.8-9.1), respectively. Corresponding estimates of the odds of type 2 diabetes, adjusted for family history of diabetes, were 1.9 (95% CI 0.5-7.1) and 7.3 (95% CI 2.2-23.7), respectively. The odds of high (> or =30.0 mU/liter) fasting insulin levels in subjects with impaired glucose tolerance were 6.9 (95% CI 0.6-74.2) and 21.0 (95% CI 2.1-206.4) for short and long durations of obesity, respectively. Corresponding estimated odds of low 2-hour insulin response (< or =71.9 mU/liter) were 0.7 (95% CI 0.2-2.9) and 3.3 (95% CI 1.2-8.9). Homeostasis model assessment of insulin resistance yielded an odds ratio of 6.7 (95% CI 0.6-73.4) for a short duration of obesity and 20.0 (95% CI 2.0-200.6) for a long duration. Examination of beta-cell function with homeostasis model assessment resulted in odds ratios of 0.2 (95% CI 0.0-1.6) and 2.0 (95% CI 0.7-5.4) for short and long durations of obesity, respectively. These data indicate that obesity decreases glucose tolerance by way of progressively increased insulin resistance and, in the case of prolonged duration, by decreased insulin secretion as well.

Is colonoscopic surveillance reducing colorectal cancer mortality in ulcerative colitis? A population based case control study.

BACKGROUND: Colonoscopic surveillance is a standard procedure in many patients with long standing, extensive ulcerative colitis (UC), in order to avoid death from colorectal cancer. No conclusive proof of its benefits has been presented however. AIMS: To evaluate the association between colonoscopic surveillance and colorectal cancer mortality in patients with UC. PATIENTS: A population based, nested case control study comprising 142 patients with a definite UC diagnosis, derived from a study population of 4664 patients with UC, was conducted. METHODS: Colonoscopic surveillance in all patients with UC who had died from colorectal cancer after 1975 was compared with that in controls matched for age, sex, extent, and duration of the disease. Information on colonoscopic surveillance was obtained from the medical records. RESULTS: Two of 40 patients with UC and 18 of 102 controls had undergone at least one surveillance colonoscopy (relative risk (RR) 0.29, 95% confidence interval 0.06 to 1.31). Twelve controls but only one patient with UC had undergone two or more surveillance colonoscopies (RR 0.22, 95% confidence interval 0.03 to 1.74), indicating a protective dose response relation. CONCLUSION: Colonoscopic surveillance may be associated with a decreased risk of death from colorectal cancer in patients with long standing UC.

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.

Food frequency questionnaire versus 7-day weighed dietary record information on dietary fibre and fat intake in middle-aged Swedish men.

To study the magnitude of agreement between a short self-administered food frequency questionnaire and a 7-day weighed dietary record regarding the consumption of fibre and fat, we collected information from 92 randomly selected middle-aged Swedish men. The participants first recorded all foods and drinks consumed over seven consecutive days by means of a digital scale. One month after the 7-day weighed record had been completed, a self-administered food frequency questionnaire on habitual consumption of foods containing fibre or fat during the preceding month was sent to the subjects. The 20 largest contributors of fibre and fat in the diet accounted for 71% and 52% of the total intake, respectively, based on the 7-day weighed record. The estimated mean consumption of fibre was 19.0 grams per day based on the 7-day weighed record and 18.3 grams per day based on the food frequency questionnaire. Corresponding estimated mean consumption of fat was 88.6 grams per day versus 46.9 grams per day. Men with high physical activity and low BMI, respectively, had higher intake of fibre and fat. These differences were seen for both dietary measurement methods but were more marked using the 7-day weighed record. The agreement between methods for each individual was also assessed. Based on five categories of fibre consumption, 61% of the respondents in the highest quintile according to the 7-day weighed record were classified in one of the two highest quintiles according to the food frequency questionnaire. The corresponding figure for fat intake was 56%. We conclude that the short self-administered food frequency questionnaire used in the present study can assess the absolute intake of fibre, but not of fat, with good precision. Also, the ranking of individuals in broad categories of consumption of fibre and fat was not largely misclassified based on this short questionnaire.

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.

Incidence of Crohn's disease in Stockholm County 1955-1989.

AIM: To evaluate the incidence of Crohn's disease in Stockholm County between 1955 and 1989. METHODS: A cohort of 1936 patients with Crohn's disease was retrospectively assembled. Incidence rates and changes in disease distribution were assessed. RESULTS: The mean increase in incidence was 15% (95% confidence intervals 12% to 18%) per five year period with a mean annual incidence rate at 4.6/10(5) during the last two decades. The mean incidence for the entire study period was similar for men and women. The mean age at diagnosis increased from 25 years in 1960-64 to 32 years in 1985-89, partly because of an increasing proportion of patients aged at least 60 years at diagnosis. The proportion of patients with colonic Crohn's disease at the time of diagnosis increased from 15% to 32% (17% difference; 95% confidence intervals 12% to 23%) whereas the proportion of patients with ileocaecal disease decreased from 58% to 41% (17% difference; 95% confidence intervals 10% to 24%) during the study period. Elderly patients had a higher proportion of small bowel disease and a lower proportion of ileocolonic disease compared with the younger patients. CONCLUSION: The incidence rate of Crohn's disease in Stockholm has stabilised at 4.6/10(5) and the proportion of elderly patients has increased during a 35 year period. Colonic Crohn's disease has increased in frequency with a reciprocal decrease in ileocaecal disease.