Development and external validation of a prediction model for patient-relevant outcomes in patients with chronic widespread pain and fibromyalgia.

BACKGROUND: The objective of this study was to develop prediction models and explore the external validity of the models in a large sample of patients with chronic widespread pain (CWP) and fibromyalgia (FM). METHODS: Patients with CWP and FM referred to rehabilitation services in Norway (n = 986) self-reported data on potential predictors prior to entering rehabilitation, and self-reported outcomes at one-year follow-up. Logistic regression models of improvement, worsening and work status, and a linear regression model of health-related quality of life (HRQoL), were developed using lasso regression. Externally validated estimates of model performance were obtained from the validation set. RESULTS: The number of participants in the development and the validation sets was 771 and 215 respectively; only participants with outcome data (n = 519-532 and 185, respectively) were included in the analyses. On average, HRQoL and work status changed little over one year. The prediction models included 10-11 predictors. Discrimination (AUC statistic) for prediction of outcome at follow-up was 0.71 for improvement, 0.67 for worsening, and 0.87 for working. The median absolute error of predictions of HRQoL was 0.36 (0.22-0.51). Reasonably good predictions of working at follow-up and HRQoL could be obtained using only the baseline scores as predictors. CONCLUSIONS: Moderately complex prediction models (10-11 predictors) generated poor to excellent predictions of patient-relevant outcomes. Simple prediction models of working and HRQoL at follow-up may be nearly as accurate and more practical. SIGNIFICANCE: Prediction modelling of outcome in rehabilitation has been sparsely explored. Such models may guide clinical decision-making. This study developed and externally validated prediction models for outcomes of people with chronic widespread pain and fibromyalgia in a rehabilitation setting. Multivariable prediction models generated poor to excellent predictions of patient-relevant outcomes, but the complexity of these models may reduce their clinical utility. Simple univariable prediction models were nearly as accurate and may have more potential for use in clinical practice.

Hyponatremia complicating labour--rare or unrecognised? A prospective observational study.

OBJECTIVE: The aim of this study was to investigate the occurrence of hyponatraemia following delivery, with a hypothesis that hyponatraemia has a high prevalence in labouring women. DESIGN: Prospective observational study. SETTING: Consultant-led delivery suite in County Hospital, Kalmar, Sweden. SAMPLE: A total of 287 pregnant women at term (37 full gestational weeks). METHODS: Oral fluids were allowed during labour. Blood samples were collected on admission, after delivery, and from the umbilical artery and vein. MAIN OUTCOME MEASURE: Hyponatraemia defined as plasma sodium < or =130 mmol/l after delivery. RESULTS: Hyponatraemia was found in 16 (26%) of the 61 mothers who received more than 2500 ml of fluid during labour. Two-thirds of fluids were orally ingested. Decrease in plasma sodium concentration during labour correlated with duration of labour and the total fluid volume administered. Analysis by multivariate logistic regression showed that hyponatraemia was significantly correlated with fluid volume (P < 0.001) but not with oxytocin administration or epidural analgesia. Hyponatraemia correlated significantly with prolonged second stage of labour, instrumental delivery, and emergency caesarean section for failure to progress (P = 0.002). CONCLUSIONS: Hyponatraemia is not uncommon following labour. Tolerance to a water load is diminished during labour; therefore, even moderate fluid volumes may cause hyponatraemia. Women should not be encouraged to drink excessively during labour. Oral fluids, when permitted, should be recorded, and intravenous administration of hypotonic fluids should be avoided. When abundant drinking is unrecognised or intravenous fluid administration liberal, life-threatening hyponatraemia may develop. The possibility that hyponatraemia may influence uterine contractility merits further investigation.

[Review of claims from the Patient Insurance: spinal anesthesia is not completely without risks]. / Fallgenomgång från patientförsäkringen: ryggbedövning inte helt komplikationsfri.

The Patient Injury Claims Department in Sweden grants compensation to patients who have incurred injury in the national health service system. All claims involving spinal and epidural anaesthesia were studied during the period 1997-1999. Serious neurological complications were behind 29 out of 65 claims. These occurred more frequently after epidural anaesthesia (1:4,000) than after spinal anaesthesia (1:13,000) with the exclusion of obstetric epidural anaesthesia (1:40,000). Epidural haematoma occurred in 1:30,000 after epidural anaesthesia, in 1:200,000 after spinal anaesthesia. One epidural abscess occurred in 60,000 epidural anaesthesias, while five cases of meningitis occurred after spinal anaesthesia (1:40,000).

[Meningitis is a rare complication of spinal anesthesia. Good hygiene and face masks are simple preventive measures]. / Meningit ovanlig komplikation i samband med spinalanestesi. God hygien och munskydd enkla förebyggande åtgärder.

Although bacterial meningitis is a rare sequela of spinal anaesthesia, occasional case reports continue to appear in anaesthesiological literature. The article presents nine cases of iatrogenic meningitis reported to the treatment injury claims authority. Eight of these patients had undergone spinal anaesthesia, and one myelography. Alpha-haemolytic streptococci were isolated in cerebrospinal fluid culture in seven cases, the remaining two cases being culture-negative. Although alpha-haemolytic streptococci are normal commensals of the upper respiratory tract and mouth and rarely cause spontaneous meningitis, they have been implicated in several reported cases of iatrogenic meningitis. The risk of such infection raises the issue of the widespread habit of omitting face masks when performing dural puncture. As these bacteria are not known to cause infection in general surgery, the necessity of using face masks in the operating theatre has been questioned. However, the use of face masks has been shown to reduce the risk of bacterial contamination from the upper airway; and as available documentation on iatrogenic meningitis suggests oral commensals to be responsible, the use of face masks should be mandatory whenever any kind of lumbar puncture is performed.