Research suggests that heredity and early fetal development play a causal role in autism. This case-control study explored the association between perinatal factors, parental psychiatric history, socioeconomic status, and risk of autism. The study was nested within a cohort of all children born in Denmark after 1972 and at risk of being diagnosed with autism until December 1999. Prospectively recorded data were obtained from nationwide registries in Denmark. Cases totaled 698 children with a diagnosis of autism; each case was individually matched by gender, birth year, and age to 25 controls. Analyses by conditional logistic regression produced risk ratios and 95% confidence intervals. Adjusted analyses showed that the risk of autism was associated with breech presentation (risk ratio (RR) = 1.63, 95% confidence interval (CI): 1.18, 2.26), low Apgar score at 5 minutes (RR = 1.89, 95% CI: 1.10, 3.27), gestational age at birth <35 weeks (RR = 2.45, 95% CI: 1.55, 3.86), and parental psychiatric history (schizophrenia-like psychosis: RR = 3.44, 95% CI: 1.48, 7.95; affective disorder: RR = 2.91, 95% CI: 1.65, 5.14). Analyses showed no statistically significant association between risk of autism and weight for gestational age, parity, number of antenatal visits, parental age, or socioeconomic status. Results suggest that prenatal environmental factors and parental psychopathology are associated with the risk of autism. These factors seem to act independently.

The aim of the present study was to assess, compare, and correlate the pain response to an experimental pain stimulus (hyperalgesia to pressure pain threshold (PPT) measured from different body sites), the pain intensity (VAS) of the habitual pain, and quality of life parameters (SF-36) in groups of females with chronic non-malignant pain syndromes. Forty female pain patients with fibromyalgia/whiplash (n = 10), endometriosis (n = 10), low back pain (n = 10), or rheumatoid arthritis (n = 10), as well as 41 age-matched healthy female controls participated in the study. The fibromyalgia/whiplash patients scored significantly higher (p < 0.04) VAS ratings (median rating = 7.0) than the endometriosis (6.0), low back pain (6.0), and rheumatoid arthritis (3.5) patients. All fours patient groups had significantly lower PPTs at all sites as compared with controls. The fibromyalgia/whiplash patients experienced the highest influence of pain on their overall health status, particularly vitality, social function, emotional problems, and mental health. A significant negative correlation was found between VAS rating and quality of life (p < 0.04). Significant correlation (p < 0.05) was found between pressure hyperalgesia measured at lowest PPT sites and the impairment of SF-36 physical function as well as mental health parameters. This study demonstrates significant generalised pressure hyperalgesia in four groups of chronic pain patients, correlations between degree of pressure hyperalgesia and impairment of some quality of life parameters, and increased pain intensity of the ongoing pain is associated with decreased quality of life.

IntroductionMyalgic encephalomyelitis (ME)/chronic fatigue syndrome (CFS) is a common, severe condition affecting 0.2 to 0.4 per cent of the population. Even so, no recent international EQ-5D based health-related quality of life (HRQoL) estimates exist for ME/CFS patients. The main purpose of this study was to estimate HRQoL scores using the EQ-5D-3L with Danish time trade-off tariffs. Secondary, the aims were to explore whether the results are not influenced by other conditions using regression, to compare the estimates to 20 other conditions and finally to present ME/CFS patient characteristics for use in clinical practice.Material and methodsAll members of the Danish ME/CFS Patient Association in 2013 (n=319) were asked to fill out a questionnaire including the EQ-5D-3L. From these, 105 ME/CFS patients were identified and gave valid responses. Unadjusted EQ-5D-3L means were calculated and compared to the population mean as well as to the mean of 20 other conditions. Furthermore, adjusted estimates were calculated using ordinary least squares (OLS) regression, adjusting for gender, age, education, and co-morbidity of 18 self-reported conditions. Data from the North Denmark Health Profile 2010 was used as population reference in the regression analysis (n=23,392).ResultsThe unadjusted EQ-5D-3L mean of ME/CFS was 0.47 [0.41–0.53] compared to a population mean of 0.85 [0.84–0.86]. The OLS regression estimated a disutility of -0.29 [-0.21;-0.34] for ME/CFS patients in this study. The characteristics of ME/CFS patients are different from the population with respect to gender, relationship, employment etc.ConclusionThe EQ-5D-3L-based HRQoL of ME/CFS is significantly lower than the population mean and the lowest of all the compared conditions. The adjusted analysis confirms that poor HRQoL of ME/CFS is distinctly different from and not a proxy of the other included conditions. However, further studies are needed to exclude the possible selection bias of the current study.

The whiplash syndrome has immense socio-economic impact. Despite extensive studies over the past years, the mechanisms involved in maintaining the pain in chronic whiplash patients are poorly understood. The aim of the present experimental study was to examine the muscular sensibility in areas within and outside the region involved in the whiplash trauma. Eleven chronic whiplash patients and 11 sex and age matched control subjects were included in the study. Before the experiment, the whiplash patients had pain in the neck and shoulder region with radiating pain to the arm. Five patients reported pain that was more widespread. The somatosensory sensibility in the areas over the infraspinatus, brachioradial, and anterior tibial muscles was assessed by pressure stimulation, pin-prick stimulation, and cotton swap stimulation. Infusion of hypertonic saline (5.85%, 0.5 ml) into the infraspinatus and anterior tibial muscles was performed to assess the muscular sensibility and referred pain pattern. The saline-induced muscle pain intensity was assessed on a continuous visual analogue scale (VAS). The distribution of pain was drawn on an anatomical map. The pressure pain thresholds were significantly lower in patients (P<0. 01) compared with controls: infraspinatus (mean 152.2 vs. 172.7 kPa), brachioradial (mean 70.0 vs. 363.8 kPa), and anterior tibial muscle (mean 172.7 vs. 497.8 kPa). The skin sensibility to pin-prick stimulation and cotton swap stimulation was not different between patients and controls. Infusion of hypertonic saline caused significantly higher VAS scores with longer duration in patients compared to control subjects (P<0.01). The area under the VAS-time curve was significantly (P<0.01) increased in patients compared to control subjects after injection into the infraspinatus muscle (mean 4138.1 vs. 780.0 cm s) and anterior tibial muscle (mean 4370.8 vs. 978.7 cm s). The saline infusion caused local pain defined as pain located around the injection site and referred pain areas not included in the local pain area. The area of local and referred pain were significantly larger in patients compared to control subjects (P<0.01). In the control group, the referred pain areas to infusion of hypertonic saline into the anterior tibial muscle were found at the dorsal aspect of the ankle. In contrast, the areas of referred pain were quite widespread in the patient group with both distal and proximal referred pain areas. In the present study, muscular hyperalgesia and large referred pain areas were found in patients with chronic whiplash syndrome compared to control subjects both within and outside the traumatised area. The findings suggest a generalised central hyperexcitability in patients suffering from chronic whiplash syndrome. This indicates that the pain might be considered as a neurogenic type of pain, and new pharmacological treatments should be investigated accordingly.

Children of women with schizophrenia have a considerable increased risk of death caused by sudden infant death syndrome. However, the results should be interpreted in the light of failure to adjust for socioeconomic status, substance abuse, smoking status, and psychotropic medication use.

BackgroundThe high mortality from suicide in patients admitted to hospital with an affective disorder is well documented, although specific causes of mortality and changes in mortality are less well studied.AimsTo describe the pattern of mortality in patients with affective disorder and to study changes in suicide riskduring the study period.MethodAll patients (n=54 103) admitted for the first time to a psychiatric hospital in Denmarkduring the period 1973–1993 because of affective disorder were included in this study. The mortality rate was compared with that of the general population.ResultsMortality from natural and unnatural causes was elevated in all subgroups of affective disorder. The risk of suicide among patients ill for one year or less after first admission increased during the period 1973–1993.ConclusionsMore attention should be paid to the risk of suicide and to physical illness in patients with affective disorders.

Our data suggest that advanced paternal age may be associated with an excess occurrence of some specific malformations. The association could be caused by mutations of the gametes in men induced by biological or environmental factors.

BackgroundA run chart is a line graph of a measure plotted over time with the median as a horizontal line. The main purpose of the run chart is to identify process improvement or degradation, which may be detected by statistical tests for non-random patterns in the data sequence.MethodsWe studied the sensitivity to shifts and linear drifts in simulated processes using the shift, crossings and trend rules for detecting non-random variation in run charts.ResultsThe shift and crossings rules are effective in detecting shifts and drifts in process centre over time while keeping the false signal rate constant around 5% and independent of the number of data points in the chart. The trend rule is virtually useless for detection of linear drift over time, the purpose it was intended for.