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Biomedical subjects

P Blomqvist

Publications and source records attributed to P Blomqvist.

At least 19 recordsLinked to original sources
PubMed2006

Risk for malignant lymphoma in ankylosing spondylitis: a nationwide Swedish case-control study.

BACKGROUND: Several inflammatory conditions are associated with an increased risk of lymphoma. The specific features of inflammation that mediate this risk are unknown. There are few studies on whether ankylosing spondylitis increases the risk of lymphoma. Besides inflammation-lymphoma aetiology, information on risk of lymphoma in ankylosing spondylitis is particularly important as a benchmark in the evaluation of, for example, tumour necrosis factor inhibitors. METHODS: The association between ankylosing spondylitis and malignant lymphomas overall, and separately for non-Hodgkin's lymphoma, Hodgkin's lymphoma and chronic lymphocytic leukaemia, was assessed in a nationwide, population-based case-control study of 50 615 cases of lymphoma and 92 928 matched controls by using prospectively recorded data on lymphomas from the Swedish Cancer Register (1964-2000) and data on pre-lymphoma hospitalisations for ankylosing spondylitis from the Swedish Inpatient Register (1964-2000). The odds ratios (ORs) associated with pre-lymphoma hospitalisation for ankylosing spondylitis were calculated using conditional logistic regression. RESULTS: 23 (0.05%) patients with lymphoma and 41 (0.05%) controls had a pre-lymphoma hospitalisation listing ankylosing spondylitis, relative risk = 1.0 (95% confidence interval (CI) 0.6 to 1.7). The number of discharges and the mean latency between ankylosing spondylitis and lymphoma were similar in patients and controls. Analyses restricted to lymphomas diagnosed during the 1990s showed similar results (OR = 1.3, 95% CI 0.6 to 2.5, number of exposed cases/controls = 14/21). CONCLUSIONS: On average and in the absence of tumour necrosis factor inhibitors, patients hospitalised with ankylosing spondylitis do not appreciably show an increased risk of lymphoma.

Adult↗
PubMed2005

Direct imaging of asymmetric magnetization reversal in exchange-biased Fe/MnPd bilayers by x-ray photoemission electron microscopy.

X-ray photoemission electron microscopy is used to probe the remnant magnetic domain structure in high quality, single-crystalline, exchange-biased Fe/MnPd bilayers. It is found that the induced unidirectional anisotropy strongly affects the overall magnetic domain structure. Real space images of the ferromagnetic domains provide direct evidence for an asymmetric magnetization reversal process after saturation along the ferromagnetic hard direction. The magnetization reversal occurs by moment rotation for decreasing fields while it proceeds by domain nucleation and growth for increasing fields. The observed domains are consistent with the crystallography of the bilayers and favor a configuration that minimizes the overall magnetostatic energy of the ferromagnetic layer.

Journal Article↗
PubMed2005

Spinal stenosis re-operation rate in Sweden is 11% at 10 years--a national analysis of 9,664 operations.

Re-operation rates in spinal stenosis surgery vary between 5 and 23%. Most previous studies have been based on selected patients groups. We analysed the 10-year lumbar spinal stenosis re-operation rate from comprehensive Swedish national data during 1987-1999. The mean length of stay decreased from 2 weeks in 1987 to 1 week in 1999. Of 9,664 patients, 628 (6.5%) were re-operated. Within 30 days after the first spinal stenosis operation, 0.15% of the patients were re-operated. The 1-, 2-, 5-, and 10-year re-operation rates were 2, 5, 8 and 11%, respectively. The rate lowered by 31% over time. Adding a fusion may lower the re-operation risk, an observation which can only be evaluated in randomised trial.

Aged↗
PubMed2005

Patient factors influencing the completion rate in colonoscopy.

BACKGROUND: Since its introduction in the late 1960s, the technology of colonoscopy has developed rapidly, and the competence of the endoscopists has increased. Still, a complete colonoscopy is not always possible to perform. AIM: To assess, in a population-based setting, which patient factors influence the success rate. PATIENTS AND METHODS: All colonoscopy records during 1979-1995 in one Swedish county (population 258,000) were retrieved. Information was obtained about each patient's sex and age, date of examination, the endoscopist and indications for colonoscopy, findings, type of colonoscopy and reasons for an incomplete colonoscopy. Results were assessed by univariate and multivariate analyses. RESULTS: Of 5145 colonoscopies, 4153 (81%) were complete. Completion rates were influenced by (odds ratio for completion [95% confidence intervals]): sex, male versus female (2.00 [1.39-2.86]); age, youngest quartile versus oldest quartile (1.49 [1.04-2.13]); indication for colonoscopy, previous colonic surgery or long-standing colitis versus other indications (2.08 [1.23-3.45]); and diverticulosis, presence versus no presence (0.79 [0.62-0.99]). The time period (proxy variable for the development of endoscopes) had no impact on completion rates. CONCLUSIONS: The completion rate was lower than that has been reported from previous hospital-based studies. Lower completion rates were found in women, older patients and in patients with diverticulosis. Higher completion rates were noted in patients with previous colonic surgery and long-standing colitis. The completion rates were not influenced by the development of the endoscopes.

Adult↗
PubMed2005

Liver operations in Sweden in 1987-99.

BACKGROUND AND AIMS: Liver surgery is developing with new techniques and treatment modalities. The aim of this study is to describe liver surgery over a long period of time in a country with a public health care system. PATIENTS AND METHOD: A register study including adult patients admitted for liver resection in Sweden (population 8.8 million) selected from the Inpatient Register 1987-99. Additional data were collected from the Swedish Cancer Register and the Cause of Death Register. Analyses of the patients, indications, mortality and causes of death are presented. RESULTS: 2,405 operations were performed (21 per million per year). The most frequent indication was colorectal metastases (27%). The 5-year survival after an operation for primary liver cancer and colorectal liver metastases was 27% and 26%, respectively. CONCLUSIONS: Few patients were admitted for liver operations compared to expected figures. The survival rates are in conformity with those previously published. With an increasing awareness of the relatively favourable prognosis and the introduction of new methods, the volume of liver operations will probably increase in Sweden.

Adolescent↗
PubMed2005

Health-related quality of life in patients before and after surgery for a herniated lumbar disc.

We investigated the pre-operative and one-year post-operative health-related quality of life (HRQOL) outcome by using a Euroqol (EQ-5D) questionnaire in 263 patients who had undergone surgery for herniation of a lumbar disc. Data from the National Swedish Register for lumbar spinal surgery between 2001 and 2002 were used and, in addition, a comparison between our cohort and a Swedish EQ-5D population survey was performed. We analysed the pre- and post-operative quality of life data, age, gender, smoking habits, pain and walking capacity. The mean age of the patients was 42 years (20 to 66); 155 (59%) were men and 69 (26%) smoked. Pre-operatively, 72 (17%) could walk at least 1 km compared with 200 (76%) postoperatively. The mean EQ-5D score improved from 0.29 to 0.70, and the HRQOL improved in 195 (74%) of the patients. The pre-operative score did not influence the post-operative score. In most patients, all five EQ-5D dimensions improved, but did not reach the level reported by an age- and gender-matched population sample (mean difference 0.17). Predictors for poor outcome were smoking, a short pre-operative walking distance, and a long history of back pain.

Adult↗
PubMed2004

Intestinal obstruction after inguinal and femoral hernia repair: a study of 33,275 operations during 1992-2000 in Sweden.

The risk of intra-abdominal intestinal obstruction after open or laparoscopic hernioplasty is, to our knowledge, not known. The transabdominal laparoscopic (TAPP) route brings a potential risk of abdominal adhesions, which may increase the risk of postoperative intestinal obstruction. The pre-peritoneal route laparoscopically, totally extraperitoneal laparoscopic hernioplasty (TEP), should not increase this risk since the abdominal cavity is not entered. The Swedish Hernia Register, with 33,275 patients operated on for single primary unilateral groin hernia during the period 1992-2000, was linked to the Swedish Inpatient register and the Swedish Death register for the period 1987-2000. The risk of postoperative intestinal obstruction was low, 1.02 per 1,000 personyears. The highest adjusted relative risks (RR) were found in patients with previous admissions for abdominal inflammations or operations. The risk increased with the number of admissions. After an acute operation, and in patients older than 60 years, there was also a significantly increased risk. The RR was 2.79 (95% CI 1.01-7.42) after TAPP and 0.57 (95% CI 0.07-4.33) following TEP compared to patients operated on by the Lichtenstein method. None of the patients undergoing open hernia operations had a significantly increased risk. TAPP increased the risk of postoperative intestinal obstruction, but other risk factors, especially previous abdominal surgery or inflammation, have greater influence.

Adolescent↗
PubMed2004

Results from a nationwide postmarketing cohort study of patients in Sweden treated with etanercept.

OBJECTIVES: To describe a nationwide system for postmarketing follow up of new antirheumatic drugs in Sweden, and to analyse safety and effectiveness in an etanercept treated patient cohort. METHODS: Etanercept became available in Sweden for prescribing on a named patient basis in 1999. All patients treated were included in a follow up of intensified adverse event reporting and recording of clinical outcome during 24 months, according to the EULAR core set. RESULTS: The mean (SD) disease activity score (DAS 28) value at inclusion among 820 patients recruited on a named patient basis during year 1 was 5.99 (1.19). After two years, 21% (n = 172) of these patients had discontinued the treatment. Of the remaining 648 patients, 68% (n = 442) responded to the treatment. However, in 55% of the responders, the disease activity was intermediate or high (mean DAS 28, 3.37 (1.20)). In all, 540 adverse events were reported in 421 adverse drug reaction (ADR) reports, in 294 patients. The events in 80 reports (19%) were serious. Twenty two per cent of the events were infections, of which 24% (n = 29) were serious. The incidence of serious adverse events remained constant over time. CONCLUSIONS: At start of etanercept treatment, patients had high disease activity. Activity remained high in a large proportion of the responding patients. Although serious ADRs occurred during late phases of treatment, no unexpected safety problems arose. No specific indicators of ADR risk were found. The monitoring system that was established may be useful in future postmarketing surveillance.

Adult↗
PubMed2004

Troponin T-values provide long-term prognosis in elderly patients undergoing non-cardiac surgery.

BACKGROUND: The aim of this study was to evaluate the significance of elevated postoperative Troponin T (TnT) levels in an elderly population undergoing non-cardiac surgery. METHODS: Five hundred and forty-six consecutive patients aged 70 years or older undergoing non-cardiac surgery of >30-min duration were enrolled in this prospective, observational study. A postoperative TnT measurement was obtained on the 5th to 7th postoperative day. Troponin T values greater than 0.02 ng ml(-1) were considered positive. Patients were followed over a 1-year period, and mortality and non-fatal cardiac events (acute myocardial infarction and coronary interventions) were recorded. RESULTS: Troponin T concentrations greater than 0.02 ng ml(-1) were detected in 53 of the study subjects (9.7%). Eleven per cent of the patients with elevated TnT had electrocardiographic or clinical signs of myocardial ischemia. One year after surgery, 17 (32%) of the patients with abnormal TnT concentrations had died. In a multivariate Cox regression analysis adjusting for baseline and perioperative data, a TnT value >0.02 ng ml(-1) was an independent correlate of the mortality adjusted hazard ratio (HR): 14.9 (95% CI 3.7-60.3). Other independent predictors of death were tachycardia (HR, 14.9 95% CI 3.45-64.8), ASA 4 (HR, 8.1 95% CI 1.3-50.0), reoperation (HR, 6.4 95% CI 1.1-36.9), and use of diuretics (HR, 4.2 95% CI 1.3-13.8). CONCLUSION: We conclude that elevated TnT levels in the postoperative period confer a 15-fold increase in mortality during the first year after surgery. Our findings also provide evidence that silent myocardial ischemia is common in an elderly population. Routine perioperative surveillance for TnT might therefore be of use in detecting patients at an increased risk of mortality during the first postoperative year.

Aged↗
PubMed2004

Surgery for herniation of a lumbar disc in Sweden between 1987 and 1999. An analysis of 27,576 operations.

The National Inpatient Register and the Swedish Death Register were linked to determine the incidence of surgical intervention, the trends and characteristics of the patients, the death rate and the pre- and post-operative admissions for herniation of a lumbar disc based on comprehensive national data between 1987 and 1999. There were 27,576 operations which were followed cumulatively for 155,249 years, with a median of 6.0 years. The mean annual rate of operation was 24 per 100,000 inhabitants, the median age of the patients was 42 years. The 30-day death rate was 0.5 per 1000 operations. The rates of re-operation at one and ten years were 5% and 10%, respectively, decreasing significantly (40%) with time. The mean length of stay decreased from nine to five days. Patients who had been in hospital because of a previous spinal disorder had a significantly higher risk of readmission.

Adult↗
PubMed2003

Spinal stenosis surgery in Sweden 1987-1999.

Despite being recognised for many years as a clinical diagnosis, no exact definition of spinal stenosis has yet been agreed, leading to difficulties in interpreting and comparing studies of the incidence, prevalence and treatment. This study presents the first analysis of national data to be reported. It is a retrospective population-based national register study, aimed at analyzing surgical interventions in patients with lumbar spinal stenosis, patient characteristics, subsequent development, and case fatality rate, based on Swedish national data for 1987-1999. Complete follow-up data were obtained of incidence and type of spinal stenosis surgery, rate of multiple operations, mortality, underlying causes of death, length of hospital stay, and case fatality rate by linkage of the National Inpatient Register and Swedish Death Register. The study cohort consisted of 10,494 patients. Laminectomy was performed in 89%, and additional fusion in 11%. The mean annual rate of operations was 9.7 per 100,000 inhabitants, the annual number of operations performed increased from 4.7 to 13.2 per 100,000 inhabitants per year. The case fatality rate within 30 days after surgery was 3.5 per 1000 operations. Cardiovascular disease was the most common cause of death (46%). Relative risk of dying within 30 days of admission was doubled in men, and for fusion surgery, and increased four fold in patients older than 80 years. The relative risk of dying decreased during the study period. The results show that spinal stenosis surgery in Sweden has increased, and is associated with a low risk. Within an ageing group of patients, mortality has declined.

Age Factors↗
PubMed2003

Colorectal cancer detection by colonoscopy in a Swedish county, 1979-95.

BACKGROUND: Colorectal cancer is the third most common cancer in Sweden, and incidence is increasing. We analysed colorectal cancer detection by colonoscopy in a defined population in Sweden. METHODS: All colonoscopy records for the period 1979-95 in one Swedish county (population 258,000) were retrieved. Information was obtained about patient demographics, date of examination, endoscopists, indications, findings, colonoscopy type and completion level. Records were linked to the Swedish Cancer Register and the Cause of Death Register. RESULTS: The majority of 2214 colorectal cancers were detected by means other than colonoscopy. In total, 192 were diagnosed and 6 were not detected by colonoscopy, with no significant differences in gender, age, indications, presence of polyps or diverticulosis, time-period or experience of the endoscopist. The mean completion rate of the endoscopist was lower in patients with undetected cancers. Coexisting inflammatory bowel disease was more common in patients with late diagnosis. Sensitivity was 97.0%, and higher when the indication was bleeding, cancer or unclear X-ray findings. CONCLUSIONS: Sensitivity in detecting colorectal cancer was high, and the proportion detected by colonoscopy increased over time. Mean completion rate was lower in patients with undetected cancers. Coexisting IBD was more common in patients with a late diagnosis.

Aged↗
PubMed2003

Cancer incidence among patients with ankylosing spondylitis in Sweden 1965-95: a population based cohort study.

BACKGROUND: Ankylosing spondylitis (AS) is a chronic inflammatory joint disease which may lead to extra-articular complications. The disease associated cancer risk has been poorly explored. Recently, tumour necrosis factor alpha blockers have been found to be efficacious in AS, but their long term risk is unknown. OBJECTIVE: To analyse a large national cohort of patients with AS to determine the overall cancer risk in AS as a background to the future introduction of new treatments. METHODS: All patients with AS admitted to Swedish hospitals 1965-95 were linked through individual national registration numbers to the Swedish Cancer Register and National Death Register. Standardised incidence ratio (SIR) of cancer risk was calculated in 6621 people, monitored during 67 885 person-years. RESULTS: No overall increase in cancer risk was found (SIR 1.05, 95% CI 0.94 to 1.17). Rectal cancer was less common (SIR 0.41, 95% CI 0.15 to 0.89) while unspecified kidney cancer was more common (SIR 5.90, 95% CI 1.61 to 15.1). Risks for colon, renal parenchymal, and renal pelvic cancer were not significantly increased. Laryngeal cancer was more common than expected, while lung cancer was not. Risks of haematopoietic malignancies were not increased. CONCLUSIONS: No overall increase in cancer risk was found. The decreased risk of rectal cancer might be due to local application of NSAIDs, and the increased risk of unspecified kidney cancer to frequent radiological pelvic examinations. If information on disease characteristics, including HLA-B27, was available for individual patients with cancer, risk-benefit analysis of long term effects of new immunomodulation treatment might be improved.

Adolescent↗
PubMed2001

Phytoplankton responses to biomanipulated grazing pressure and nutrient additions--enclosure studies in unlimed and limed Lake Njupfatet, central Sweden.

Enclosure experiments aimed to assess the role of Chaoborus larvae in regulating lower trophic levels under natural and nutrient-enriched conditions were performed in situ in the dimictic, oligotrophic clearwater Lake Njupfatet, central Sweden. One experiment was performed before, and one after, whole-lake calcite treatment. In the acidic system, total planktonic biomass (TPB; the sum of phyto-, bacterio-, protozoo-, and metazooplankton), dominated by the cyanobacterium Merismopedia, was only weakly stimulated by the nutrients while the predator had no effect. In the limed environment, TPB increased strongly in response to the nutrients in combination with a negative response to the predator. Principally phytoplankton, but also bacterioplankton and protozooplankton (ciliates) were stimulated by the nutrients. It is argued that Merismopedia acted as a dead-end in the energy flow in the acidic system. Liming resulted in the disappearance of Merismopedia and this opened the flow of material to higher trophic levels. Since liming also led to a significant reduction in the concentrations of phosphorus in the lake water, it is proposed that a combination of liming and gentle fertilization might be used to restore the productivity of acidified lakes.

Acid Rain↗
PubMed2001

A 10-year survey of inflammatory bowel diseases-drug therapy, costs and adverse reactions.

BACKGROUND: Drug therapy for Crohn's disease and ulcerative colitis is based on anti-inflammatory and immunodulating drugs, nutritional support and surgical resection. Recently, new drugs have been introduced. AIM: To report drug prescriptions, costs and adverse reactions among inflammatory bowel disease patients in Sweden between 1988 and 1997. METHODS: Drug use was calculated from the national Diagnosis and therapy survey and drug costs from prescriptions and drug sales. Adverse drug reactions were obtained from the Medical Products Agency's National Pharmacovigilance system. RESULTS: The annual drug exposure for Crohn's disease was 0.55 million daily doses per million population, mainly supplementation and aminosalicylic acids. Mesalazine and olsalazine had 61% within this group. For ulcerative colitis patients, drug exposure was 0.61 million daily doses per million per year and aminosalicylic acids fell from 70% to 65%. For inflammatory bowel disease patients, corticosteroids and nutritional supplementation were common. The annual average cost for inflammatory bowel disease drugs was 7.0 million US dollars. Annually, 32 adverse drug reactions were reported, mainly haematological reactions such as agranulocytosis and pancytopenia (60%), followed by skin reactions. Only two deaths were reported. Aminosalicylic acids were the most commonly reported compounds. CONCLUSIONS: Drug use for inflammatory bowel disease in the pre-biologic agent era rested on aminosalicylic acid drugs and corticosteroids with stable levels, proportions and costs. The level of adverse drug reactions was low but haematological reactions support the monitoring of inflammatory bowel disease patients.

Adult↗
PubMed2001

The impact of endoscopists' experience and learning curves and interendoscopist variation on colonoscopy completion rates.

BACKGROUND AND STUDY AIMS: Since its introduction in the late 1960s, the technology of colonoscopy has developed rapidly and the competence of endoscopists has increased. Nevertheless, it is not always possible to perform a complete colonoscopy. The aim of this study was to assess, in a population-based setting, the endoscopist-related factors influencing the completion rate, taking into account patient characteristics and changes in the technology over time. PATIENTS AND METHODS: All colonoscopy records between 1979 and 1995 in one Swedish county (population 258,000) were retrieved. Information was obtained about patient demographics, date of examination, endoscopist, indications, presence of diverticulosis, type of colonoscopy, findings, level of completion, complications, and reasons for incomplete colonoscopy. Completion rates were examined by univariate and multivariate analyses. RESULTS: Of 5,494 colonoscopies, 4,153 (75%) were complete, and 78% were diagnostic and 22% therapeutic. In 70 %, findings were pathological, and 30 % were normal. The overall 30-day endoscopist-related complication rate was 0.3 %. Over time, the proportion of colonoscopies performed by endoscopists with greater experience increased and so did the completion rates. Completion rates were influenced by endoscopist's experience and to some extent by the intensity (the number of colonoscopies performed by the endoscopist during the previous 90 days). There was a large interendoscopist variation, at each level of experience, in the ability to perform a complete colonoscopy, implying substantial differences between individual learning curves. CONCLUSIONS: The completion rate has increased over time, the major reason being greater competence of endoscopists. The finding of large interendoscopist variation, at each level of experience, in the ability to perform a complete colonoscopy supports the monitoring of endoscopists to maintain and improve performance.

Adolescent↗
PubMed2001

Complications of diagnostic and therapeutic colonoscopy within a defined population in Sweden.

BACKGROUND: Colonoscopy, introduced in the late 1960s, has become the principal method for diagnosis, treatment, and follow-up of colorectal diseases. Being invasive, colonoscopy is associated with a risk of complications. The aim of this study was to analyze the rate of complications of diagnostic and therapeutic colonoscopy in a population-based setting. METHODS: All colonoscopy records for 1979 to 1995 in 1 Swedish county (population 258,000) were retrieved. Information was obtained about patients' demographics, date of examination, endoscopist, indications, findings, colonoscopy type, completion level, and complications. Records were linked to the Cause of Death Register and the Swedish Hospital Discharge Register to ascertain mortality and morbidity. RESULTS: In 6066 colonoscopies, the overall morbidity was 0.4% (diagnostic 0.2%, therapeutic 1.2%). The most frequent complications were bleeding (0.2%) and perforation (0.1%), with no colonoscopy-related mortality. Bleeding was confined to therapeutic colonoscopy and occurred immediately, mainly after removal of large polyps with thick stalks. Perforations at diagnostic colonoscopy occurred in the left colon; they were diagnosed sooner than perforations associated with therapeutic colonoscopy where the cecum was the most frequent site. The bleeding rate was correlated to the experience of the endoscopists. CONCLUSIONS: Colonoscopy is a safe procedure, and the rate of adverse events in this population-based setting was low.

Colon↗