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Biomedical subjects

P G Persson

Publications and source records attributed to P G Persson.

At least 37 records · Page 2Linked to original sources
PubMed1997

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.

Adolescent↗
PubMed1997

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.

Aged↗
PubMed1997

Evaluation of surveillance programmes for colorectal cancer in ulcerative colitis patients by case-control studies: methodological considerations.

OBJECTIVES: The evaluation of the efficacy of colonoscopy screening in patients with ulcerative colitis for colorectal cancer is associated with methodological difficulties. Case-control studies can, however, be used to determine the efficacy of such a programme and the outline of the methodology in such a programme is presented. METHODS: The randomised controlled trial provides perspective for case-control studies of screening efficacy. Cases are selected from persons who have ulcerative colitis with manifestations of colorectal cancer: for example, those who have died of colorectal cancer or have symptomatic metastases. Controls are selected from persons who have ulcerative colitis, who had been alive when the case died of colorectal cancer, and who had been subject to the risk of dying from, but had not had, colorectal cancer diagnosed when the case was diagnosed with colorectal cancer. The relevant screening history for cases begins with the case's diagnosis of ulcerative colitis and ends with the cases diagnosis of colorectal cancer; that for controls should be comparable to that for cases to avoid bias. Cases and controls are compared with respect to their "exposure" to colonoscopy during their screening histories: the occurrence of any screening, which took place during the period of time that an occult tumour (or an identifiable lesion) may plausibly have been present. CONCLUSION: The proposed methodology can evaluate the efficacy of a screening programme rapidly, practically, and ethically.

Case-Control Studies↗
PubMed1996

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.

Adult↗
PubMed1996

Survival and cause-specific mortality in inflammatory bowel disease: a population-based cohort study.

BACKGROUND & AIMS: A population-based cohort study of 1251 subjects with Crohn's disease and 1547 subjects with ulcerative colitis, diagnosed in Stockholm between 1955 and 1984, was performed to examine the survival, changes in survival over time, and cause-specific mortality. METHODS: The cohort of patients was followed up in the National Cause-of-Death register until 1990. National mortality rates were used for comparisons. RESULTS: The observed vs. expected survival rate after 15 years was 93.7% (95% confidence interval [CI], 91.8%-95.7%) for Crohn's disease and 94.2% (95% CI, 92.4%-96.1%) for ulcerative colitis. Overall, 174 deaths occurred vs 115.42 expected (standardized mortality ratio, 1.51; 95% CI, 1.29-1.75) in Crohn's disease. In ulcerative colitis, 255 deaths occurred compared with 186.78 expected (standardized mortality ration, 1.37; 95% CI, 1.20-1.54). Inflammatory bowel disease was the major contributor to the elevated mortality rate, but mortality from colorectal cancer, asthma, and non-alcohol-related liver diseases was increased in ulcerative colitis; mortality from other gastrointestinal diseases was increased in ulcerative colitis as well as in Crohn's disease. CONCLUSIONS: Data in the present study are compatible with the hypothesis that subjects with inflammatory bowel disease have an increased mortality compared with the general population.

Adolescent↗
PubMed1996

Effect of prefracture versus postfracture dietary assessment on hip fracture risk estimates.

BACKGROUND: Dietary factors are presumed to have influence on bone mass and hence fracture susceptibility. Most information in this respect is based on retrospective assessment of previous dietary habits. In a population-based case-control study nested within a cohort, we collected dietary information both before and after a first hip fracture. Thus it was possible to study reported changes in dietary habits, intentional as well as unintentional, among hip fracture patients after a first hip fracture and to compare postfracture with prefracture dietary information. METHODS: More than 65 000 women born 1914-1948 in two counties in central Sweden completed a food frequency questionnaire regarding their usual current dietary habits, before attending a mammographic screening between the years 1987 and 1990. Subsequently 123 of them sustained a first hip fracture and were defined as cases in the present study. For every case, one control, individually matched by age and county of residence, was selected from the cohort. A second identical food frequency questionnaire was mailed to both cases and controls on average 2 years after the hip fracture event. In total 98 case/control pairs could be included in the analysis. The association between diet and hip fracture was evaluated and the results from the two dietary assessments were contrasted. Women who themselves claimed that they had not changed their diet in recent years were analysed separately. RESULTS: The hip fracture cases, compared with the controls, had reduced their reported dietary intake of dairy products after the fracture. Apparently this was not intentional since this effect was more pronounced among those cases who claimed that their diet was unchanged. The changes were most apparent among the younger cases with a more recent hip fracture and with a body mass index above the median. Half of the cases, more than twice the frequency in controls, who were initially classified as having high intake of dairy products were classified as having low intake (<800 mg calcium/day) after the hip fracture. This also lowered, in fact reversed, the relative risk estimates of hip fracture both for intake of dairy products and calcium. Crude odds ratios of highest quartile of intake versus lowest, changed from 3.0 to 0.6 for dairy products and from 2.6 to 0.9 for calcium. No other foods or nutrients displayed such notable differences between the two surveys. CONCLUSION: We conclude that the use of current and retrospective dietary information after a hip fracture can lead to a differential misclassification in dietary studies and to biased estimates of hip fracture risk as compared with prospectively collected dietary information.

Age Distribution↗
PubMed1996

Operative factors and the long-term incidence of acute myocardial infarction after transurethral resection of the prostate.

We studied the association between the operative course of transurethral resection of the prostate (TURP) and the morbidity of acute myocardial infarction (AMI) in a cohort comprising 846 patients who underwent this operation between 1983 and 1992. Up to the end of 1993, a total of 69 patients had developed AMI, of which 10 patients had a reinfarction. The relative risk associated with absorption of 500 ml or more of the irrigating medium during surgery was 1.6 [95% confidence interval (CI) = 0.9-3.0] for a first-time AMI after TURP, 6.1 (95% CI = 1.8-20.7) for a reinfarction, and 2.2 (95% CI = 1.3-3.9) for a first-time or a reinfarction combined. A blood loss of 275 ml or more was associated with a decreased relative risk (RR = 0.4; 95% CI = 0.2-0.8) of a first-time AMI after TURP. Patients who lost less than 275 ml of blood and absorbed 500 ml or more of irrigating fluid during surgery had 4.4 times the risk of having an acute myocardial infarction (RR = 4.4; 95% CI = 1.7-11.8). These results appear to indicate that the operative course of TURP is important to the development of AMI over an extended period of time.

Aged↗
PubMed1994

Crohn's disease and cancer: a population-based cohort study.

BACKGROUND/AIMS: To study the association between Crohn's disease and cancer, we performed a population-based study of 1251 subjects with Crohn's disease diagnosed in Stockholm from 1955 to 1984 and followed in both the National Cancer Register and the National Cause-of-Death Register until 1989. METHODS: For comparisons, regional cancer incidence rates in Stockholm County were used together with individually computed person-years at risk in the Crohn's disease cohort. RESULTS: Overall, 69 malignancies occurred among 67 individuals as compared with 59.80 expected malignancies (standardized morbidity ratio [SMR] = 1.15; 95% confidence interval, 0.90-1.46). An excess number of cancers of the upper gastrointestinal tract (SMR, 3.05; 95% confidence interval, 1.67-5.11) was observed, mainly because of an increased number of cancers of the small intestine (SMR, 15.64; 95% confidence interval, 4.26-40.06). An increased occurrence of urinary bladder cancer was also observed (SMR, 2.68; 95% confidence interval, 1.08-5.53). CONCLUSIONS: The occurrence of colorectal cancer was not increased.

Adolescent↗
PubMed1994

Do left-handers have increased mortality?

To study the association between handedness and mortality, we evaluated the experience of a Swedish population-based cohort comprising 48,964 conscripts age 18-21 years in 1969-1970. We linked this cohort to the Cause-of-Death Register through 1989. Hand preference was measured by a simple question regarding handedness; to confirm the answer, the conscript held a dummy rifle while an observer recorded whether he was a left- or right-hand shooter. A total of 954 deaths occurred in the cohort, of which 82 were among left-handers, corresponding to a relative risk estimate of 1.0 (95% confidence interval = 0.8-1.3) for left-handers compared with right-handers. The relative risk estimate of death by motor vehicle accidents was 1.3 (95% confidence interval = 0.8-2.0). The data in this study refute previous reports indicating an increased overall mortality. The results regarding motor vehicle death indicate a slightly increased relative risk associated with left-handedness.

Adolescent↗
PubMed1994

Exposure to stainless steel welding fumes and lung cancer: a meta-analysis.

Stainless steel welding is associated with exposure to metals including hexavalent chromium and nickel. This study is a meta-analysis of five studies of stainless steel welders and the occurrence of lung cancer. Asbestos exposure and smoking habits have been taken into account. The calculated pooled relative risk estimate was 1.94 with a 95% confidence interval of 1.28-2.93. This result suggests a causal relation between exposure to stainless steel welding and lung cancer.

Causality↗
PubMed1993

Risk indicators for inflammatory bowel disease.

We investigated the association between different risk indicators and inflammatory bowel disease in a case-control study based on the population of Stockholm County during 1980-1984. Information on physical activity, oral contraceptives, some previous diseases and childhood characteristics was collected using a postal questionnaire for 152 cases of Crohn's disease, 145 cases of ulcerative colitis, and 305 controls. The relative risk (RR) of Crohn's disease was inversely related to regular physical activity and estimated at 0.6 (95% CI: 0.4-0.9) and 0.5 (95% CI: 0.3-0.9) for weekly and daily exercise, respectively. Having psoriasis prior to the inflammatory bowel disease was associated with an increased relative risk of Crohn's disease (RR = 2.9, 95% CI: 1.1-7.9). Use of oral contraceptives was associated with an increased RR of 1.7 for both Crohn's disease and ulcerative colitis. Crohn's disease confined to the colon and total ulcerative colitis at diagnosis were most strongly associated with oral contraceptives.

Adolescent↗
PubMed1993

Use of oral moist snuff and inflammatory bowel disease.

We examined the association between oral moist snuff use and inflammatory bowel disease in a case-control study based on the population in Stockholm County. The relative risk (RR) associated with ever use of moist snuff was 2.1 (95% CI: 1.0-4.6) for Crohn's disease, and 2.2 (95% CI: 1.1-4.4) for ulcerative colitis. Cigarette smoking indicated a synergistic relation with moist snuff: the RR estimate of Crohn's disease was 3.7 (95% CI: 1.1-13.1) and of ulcerative colitis 3.3 (95% CI: 1.0-10.9) for snuff dippers who were also current cigarette smokers, but only 0.9 and 1.1 respectively for snuff dippers who had never smoked.

Adolescent↗
PubMed1992

Flow cytometric analysis of uterine sarcoma: ploidy and S-phase rate as prognostic indicators.

Flow cytometry of various gynecological tumors has shown that aneuploid tumors and a high S-phase rate carry a prognosis worse than that of diploid tumors or tumors with a low S-phase. The aim of this study is to investigate the prognostic importance of DNA ploidy and S-phase rate in relation to mitotic count, tumor stage, tumor grade, and histology in 37 patients with uterine sarcoma stages I-IV (FIGO). Flow cytometry was performed on archival paraffin-embedded tumor tissue and the histologic specimens were reviewed by a single pathologist. Nineteen (51%) of the tumors were classified as DNA aneuploid. The S-phase fraction (SPF) was determined in 33 cases. The mean SPF (+/- SD) was 15.0% (+/- 9.5%). The mean SPF was three times higher in aneuploid tumors than in diploid cases. Both the proportion of aneuploid tumors and the mean SPF were significantly higher in later stage tumors, more poorly differentiated tumors, and tumors with a higher mitotic index. No significant differences were seen between histologic types with respect to the two cytometric variables. The 5-year cancer survival rate was only 11% in aneuploid cases compared with 59% in diploid cases (log rank, P = 0.0002). There was a significantly worse prognosis in cases with a higher SPF (P = 0.0009) and in case with a higher mitotic index (P = 0.0016). In the multivariate survival analysis using the Cox proportional hazards model, DNA ploidy showed a significant prognostic value (P = 0.046) even when adjusted for stage, grade, and mitotic index. When adjusted for stage and grade only, SPF showed significant additional prognostic value.

Adult↗
PubMed1992

Diet and inflammatory bowel disease: a case-control study.

We conducted a population-based case-control study of inflammatory bowel disease and dietary habits in Stockholm during 1984-1987. We obtained retrospective information about food intake 5 years previously by a postal questionnaire for 152 cases with Crohn's disease, 145 cases with ulcerative colitis, and 305 controls. The relative risk of Crohn's disease was increased for subjects who had a high (55 gm or more per day) intake of sucrose (relative risk = 2.6, 95% confidence interval = 1.4-5.0) and was decreased for subjects who had a high (15 gm or more per day) intake of fiber (relative risk = 0.5, 95% confidence interval = 0.3-0.9). The most striking finding was an increased relative risk of both Crohn's disease and ulcerative colitis associated with consumption of fast foods: the relative risk associated with consumption of fast foods at least two times a week was estimated at 3.4 (95% confidence interval = 1.3-9.3) for Crohn's disease and 3.9 (95% confidence interval = 1.4-10.6) for ulcerative colitis. Although coffee seemed to provide a protective effect for both diseases, there are reasons to consider this finding an artifact.

Adolescent↗
PubMed1990

Retrospective versus original information on diet: implications for epidemiological studies.

The aim of this study was to evaluate the use of retrospective information on diet in relation to the information originally reported. Hospital controls (n = 131) who participated in a case-control study on diet and pancreatic cancer in Stockholm, Sweden, answered a second postal questionnaire four years later about their current and previous food consumption. The food consumption was dichotomized for the purpose of the analysis. In relation to the original information, the use of retrospective information overestimated previous food consumption among subjects with increased intake, while retrospective information underestimated previous food consumption among subjects with decreased intake. These tendencies were slightly more pronounced in the age group 60-79 years than in the age group 40-59 years. For subjects with unchanged food consumption, there was a high agreement between original and retrospective information. Considerable differential misclassification could be introduced in an epidemiological study if cases and non-cases differ with regard to changes in food consumption.

Adult↗
PubMed1990

Inflammatory bowel disease and tobacco smoke--a case-control study.

A case-control study was carried out in Stockholm, Sweden between 1984 and 1987 to evaluate the association of cigarette smoking and exposure to environmental tobacco smoke during childhood and the subsequent development of inflammatory bowel disease. Information on smoking was obtained by a postal questionnaire. The relative risk of Crohn's disease in current smokers compared with those who had never smoked was 1.33 (95% confidence limits 0.7; 2.6) in men and 4.99 (2.7; 9.2) in women; the corresponding results for ulcerative colitis were 0.96 (0.5; 1.8) and 0.72 (0.4; 1.4). The relative risk of ulcerative colitis in recent exsmokers compared with those who had never smoked was 2.18 (0.9; 5.0). Furthermore, an increase in the risk of Crohn's disease was found in those who were exposed to environmental tobacco smoke during childhood, the relative risk being 1.50 (1.0; 2.3). The corresponding relative risk of ulcerative colitis was 0.98 (0.6; 1.5).

Adult↗
PubMed1990

Factors affecting colectomy rate in ulcerative colitis: an epidemiologic study.

Factors affecting colectomy rate were studied in a retrospective population based series of 1586 patients with ulcerative colitis, in Stockholm County during 1955-84. Five hundred and sixty eight patients (36%) had total colitis at diagnosis, 603 patients (38%) left sided colitis, and 397 patients (25%) proctitis. During a median period of observation of 13 years 514 patients were treated by colectomy. The five, 10, and 25 year cumulative colectomy rate were 20% (CI 18-22%), 28% (CI 26-30%), and 45% (CI 41-49%) respectively. The main factor affecting the colectomy rate was the extent of disease at diagnosis. Patients with total colitis showed a five, 10, and 25 year cumulative colectomy rate of 32% (CI 28-36%), 42% (CI 38-46%), and 65% (CI 58-72%) respectively. Ten per cent of the 1586 patients had a colectomy during the first year after diagnosis, 4% during the second year and 1% during subsequent years. The age at diagnosis and sex did not affect the cumulative colectomy rate. Elective colectomy was performed in 322 cases (63%) and acute colectomy in 192. The duration of disease before colectomy fell during the study period due to a more standardised criteria for colectomy in severe attacks. One hundred and twenty nine (66%) of the acute colectomies were performed within two years from diagnosis.

Adult↗