Jan Terje Kvaløy

The effect of age of onset of PD on risk of dementia

BackgroundDementia occurs in the majority of patients with Parkinson’s disease (PD). Late onset of PD has been reported to be associated with a higher risk for dementia. However, age at onset (AAO) and age at baseline assessment are often correlated. The aim of this study was to explore whether AAO of PD symptoms is a risk factor for dementia independent of the general effect of age.MethodsTwo community-based studies of PD in New York (n = 281) and Rogaland county, Norway (n = 227) and two population-based groups of healthy elderly from New York (n = 180) and Odense, Denmark (n = 2414) were followed prospectively for 3–4 years and assessed for dementia according to DSM-IIIR. All PD and control cases underwent neurological examination and were followed with neurological and neuropsychological assessments. We used Cox proportional hazards regression based on three different time scales to explore the effect of AAO of PD on risk of dementia, adjusting for age at baseline and other demographic and clinical variables.FindingsIn both PD groups and in the pooled analyses, there was a significant effect of age at baseline assessment on the time to develop dementia, but there was no effect of AAO independent of age itself. Consistent with these results, there was no increased relative effect of age on the time to develop dementia in PD cases compared with controls.InterpretationThis study shows that it is the general effect of age, rather than AAO that is associated with incident dementia in subjects with PD.

Epidemiology of perforated peptic ulcer: Age- and gender-adjusted analysis of incidence and mortality

AIM To investigate the epidemiological trends in incidence and mortality of perforated peptic ulcer (PPU) in a well-defined Norwegian population. METHODS A retrospective, population-based, single-center, consecutive cohort study of all patients diagnosed with benign perforated peptic ulcer. Included were both gastric and duodenal ulcer patients admitted to Stavanger University Hospital between January 2001 and December 2010. Ulcers with a malignant neoplasia diagnosis, verified by histology after biopsy or resection, were excluded. Patients were identified from the hospitals administrative electronic database using pertinent ICD-9 and ICD-10 codes (K25.1, K25.2, K25.5, K25.6, K26.1, K26.2, K26.5, K26.6). Additional searches using appropriate codes for relevant laparoscopic and open surgical procedures (e.g., JDA 60, JDA 61, JDH 70 and JDH 71) were performed to enable a complete identification of all patients. Patient demographics, presentation patterns and clinical data were retrieved from hospital records and surgical notes. Crude and adjusted incidence and mortality rates were estimated by using national population demographics data. RESULTS In the study period, a total of 172 patients with PPU were identified. The adjusted incidence rate for the overall 10-year period was 6.5 per 100 000 per year (95%CI: 5.6-7.6) and the adjusted mortality rate for the overall 10-year period was 1.1 per 100 000 per year (95%CI: 0.7-1.6). A non-significant decline in adjusted incidence rate from 9.7 to 5.6 occurred during the decade. The standardized mortality ratio for the whole study period was 5.7 (95%CI: 3.9-8.2), while the total 30-d mortality was 16.3%. No difference in incidence or mortality was found between genders. However, for patients ≥ 60 years, the incidence increased over 10-fold, and mortality more than 50-fold, compared to younger ages. The admission rates outside office hours were high with almost two out of three (63%) admissions seen at evening/night time shifts and/or during weekends. The observed seasonal variations in admissions were not statistically significant. CONCLUSION The adjusted incidence rate, seasonal distribution and mortality rate was stable. PPU frequently presents outside regular work-hours. Increase in incidence and mortality occurs with older age.

Neuropsychiatric syndromes in patients with systemic lupus erythematosus and primary Sjögren syndrome: a comparative population-based study

Objectives: To compare the prevalence and pattern of neuropsychiatric (NP) syndromes observed in systemic lupus erythematosus (SLE) to patients with Primary Sjögren syndrome (PSS) using the American College of Rheumatology (ACR) criteria for the 19 NP syndromes seen in SLE. Methods: A population-based study was conducted including 68 patients with SLE (mean (SD) age 43.8 (13.6) years) and 72 with PSS (age 57.8 (13.0) years). Specialists in internal medicine, neurology and neuropsychology performed standardised examinations. Cerebral MRI scans and neurophysiological studies were performed in all patients. Results: Similar prevalences in SLE and PSS were observed for headaches (87% vs 78%, p = 0.165), cognitive dysfunction (46% vs 50%, p = 0.273), mood disorders (26% vs 33%, p = 0.376), anxiety disorders (12% vs 4%, p = 0.095), cranial neuropathy (1% vs 4%, p = 0.339) and seizure disorders (7% vs 3%, p = 0.208). Cerebrovascular disease was more common in SLE than PSS (12% vs 3%, p = 0.049); but mononeuropathy (0% vs 8%, p = 0.015) and polyneuropathy (18% vs 56%, p<0.001) were less common in SLE than PSS. Other syndromes were rare or absent in both patient groups. Conclusions: Headache, cognitive dysfunction and mood disorders are common in both diseases, but otherwise there are distinct differences in NP involvement, with cerebrovascular diseases more prevalent in SLE and neuropathies more common in PSS. This indicates that some NP disease mechanisms are shared while others differ between the two diseases.

Guaranteed Conditional Performance of Control Charts via Bootstrap Methods

To use control charts in practice, the in-control state usually has to be estimated. This estimation has a detrimental effect on the performance of control charts, which is often measured by the false alarm probability or the average run length. We suggest an adjustment of the monitoring schemes to overcome these problems. It guarantees, with a certain probability, a conditional performance given the estimated in-control state. The suggested method is based on bootstrapping the data used to estimate the in-control state. The method applies to different types of control charts, and also works with charts based on regression models. If a non-parametric bootstrap is used, the method is robust to model errors. We show large sample properties of the adjustment. The usefulness of our approach is demonstrated through simulation studies.

TTT-based tests for trend in repairable systems data

Abstract A major aspect of analysis of failure data for repairable systems is the testing for a possible trend in interfailure times. This paper reviews some important and popular graphical methods and tests for the nonhomogeneous Poisson process model. In particular, the total time on test (TTT) plot is considered, and trend tests based on the TTT-statistic are motivated and derived. In particular, a test based on the Anderson-Darling statistic is suggested. The tests are evaluated and compared in a simulation study, both with respect to the achievement of correct significance level and rejection power. The considered alternatives to ‘no trend’ are the log-linear, power law and a class of bathtub-shaped intensity functions. The simulation study involves single systems, as well as the case where several independent systems of the same kind are observed.

Survival effect of implementing national treatment strategies for curatively resected colonic and rectal cancer

The surgical management of rectal cancer has changed substantially over the past decade. There are limited data on the long‐term outcome of implementing systematic management strategies.

Development of the probability of return of spontaneous circulation in intervals without chest compressions during out-of-hospital cardiac arrest: an observational study

BackgroundOne of the factors that limits survival from out-of-hospital cardiac arrest is the interruption of chest compressions. During ventricular fibrillation and tachycardia the electrocardiogram reflects the probability of return of spontaneous circulation associated with defibrillation. We have used this in the current study to quantify in detail the effects of interrupting chest compressions.MethodsFrom an electrocardiogram database we identified all intervals without chest compressions that followed an interval with compressions, and where the patients had ventricular fibrillation or tachycardia. By calculating the mean-slope (a predictor of the return of spontaneous circulation) of the electrocardiogram for each 2-second window, and using a linear mixed-effects statistical model, we quantified the decline of mean-slope with time. Further, a mapping from mean-slope to probability of return of spontaneous circulation was obtained from a second dataset and using this we were able to estimate the expected development of the probability of return of spontaneous circulation for cases at different levels.ResultsFrom 911 intervals without chest compressions, 5138 analysis windows were identified. The results show that cases with the probability of return of spontaneous circulation values 0.35, 0.1 and 0.05, 3 seconds into an interval in the mean will have probability of return of spontaneous circulation values 0.26 (0.24–0.29), 0.077 (0.070–0.085) and 0.040(0.036–0.045), respectively, 27 seconds into the interval (95% confidence intervals in parenthesis).ConclusionDuring pre-shock pauses in chest compressions mean probability of return of spontaneous circulation decreases in a steady manner for cases at all initial levels. Regardless of initial level there is a relative decrease in the probability of return of spontaneous circulation of about 23% from 3 to 27 seconds into such a pause.

Patterns and predictive factors of complications after endoscopic retrograde cholangiopancreatography

With an increased use of magnetic resonance imaging, the indications for endoscopic retrograde cholangiopancreatography (ERCP) have changed. Consequently, the patterns and factors predictive of complications after ERCP performed during current routine clinical practice are not well known.

The Prevalence of Dementia in an Urban Turkish Population

A cross-sectional, population-based, 2-stage prevalence study was conducted in a sample of 1019 community-dwelling persons over the age of 70 years living in Istanbul. In the first phase, participants were screened with the Mini-Mental State Examination for evidence of cognitive impairment. In the second phase, 79% of those who screened positive (n = 322) and 9% of screen-negatives (n = 63) underwent a standardized diagnostic workup. Diagnosis of dementia and Alzheimers disease (AD) was made according to established criteria. Ninety-three cases of dementia were identified, 58 of whom were diagnosed with probable AD. Based on these numbers, the prevalence rates of probable AD and dementia were calculated to be 11.0% (95% CI, 7.0% to 15.0%) and 20.0% (95% CI, 14.0% to 26.0%), respectively, in this population. Prevalence rates of dementia and AD in Istanbul, Turkey, are comparable with those seen in the Western world.

Fatigue in primary Sjögren’s syndrome – A link to sickness behaviour in animals?

Interleukin-1beta (IL-1beta) is involved in the regulation of sickness behaviour in response to infection and inflammation in animals. Human fatigue can be considered an element of sickness behaviour and is a prominent and often disabling phenomenon in autoimmune diseases such as primary Sjögrens syndrome (PSS). The role of the IL-1 system in the fatigue of patients with PSS was explored. A cerebrospinal fluid (CSF) analysis of IL-1beta, IL-1Ra, and IL-1sRII was performed in 54 PSS patients and 53 control subjects. Fatigue was evaluated in the patients using the Fatigue Severity Scale (FSS) and a fatigue visual analogue scale (VAS); mood was evaluated using the Beck Depression Inventory (BDI). There were higher CSF levels of IL-1Ra pg/mL in PSS patients vs. controls (median 38.4: range 15.4-81.7 vs. 33.7: 7.3-163.1, p=0.026). Fatigue VAS scores were associated with increasing CSF levels of IL-1Ra in PSS patients (R(2)=0.11, p=0.015). In a subgroup analysis of the non-depressed PSS patients (N=37; 69%), the association between VAS scores and IL-1Ra was even stronger (R(2)=0.20, p=0.006). The positive association between VAS scores and IL-1Ra remained significant in a multiple regression analysis adjusting for age and BDI scores. Increased levels of IL-1Ra in the CSF are associated with increasing fatigue in PSS patients, indicating that the activated IL-1 system is a possible biological factor associated with fatigue.