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.

Review: Comparative methane production in mammalian herbivores.

Methane (CH4) production is a ubiquitous, apparently unavoidable side effect of fermentative fibre digestion by symbiotic microbiota in mammalian herbivores. Here, a data compilation is presented of in vivo CH4 measurements in individuals of 37 mammalian herbivore species fed forage-only diets, from the literature and from hitherto unpublished measurements. In contrast to previous claims, absolute CH4 emissions scaled linearly to DM intake, and CH4 yields (per DM or gross energy intake) did not vary significantly with body mass. CH4 physiology hence cannot be construed to represent an intrinsic ruminant or herbivore body size limitation. The dataset does not support traditional dichotomies of CH4 emission intensity between ruminants and nonruminants, or between foregut and hindgut fermenters. Several rodent hindgut fermenters and nonruminant foregut fermenters emit CH4 of a magnitude as high as ruminants of similar size, intake level, digesta retention or gut capacity. By contrast, equids, macropods (kangaroos) and rabbits produce few CH4 and have low CH4 : CO2 ratios for their size, intake level, digesta retention or gut capacity, ruling out these factors as explanation for interspecific variation. These findings lead to the conclusion that still unidentified host-specific factors other than digesta retention characteristics, or the presence of rumination or a foregut, influence CH4 production. Measurements of CH4 yield per digested fibre indicate that the amount of CH4 produced during fibre digestion varies not only across but also within species, possibly pointing towards variation in microbiota functionality. Recent findings on the genetic control of microbiome composition, including methanogens, raise the question about the benefits methanogens provide for many (but apparently not to the same extent for all) species, which possibly prevented the evolution of the hosting of low-methanogenic microbiota across mammals.

Measurement properties for the revised patient-reported OsteoArthritis Quality Indicator questionnaire.

OBJECTIVES: To assess validity, reliability, responsiveness and interpretability of the revised OsteoArthritis Quality Indicator (OA-QI) questionnaire version 2 (v2) assessing patient-reported quality of osteoarthritis care. METHODS: The OA-QI v2 (16 items, score range 0-100 (100 = best score)) was included in a longitudinal cohort study. Attendees of a 4.5 h osteoarthritis patient education programme at Diakonhjemmet Hospital, Norway, completed the OA-QI at four time points: 2 weeks before, immediately before, immediately after, and 3 months after the programme. Test-retest reliability and measurement error over a 2-week time period were assessed in those that had not seen health professionals in the interim. Construct validity and responsiveness were assessed with predefined hypotheses. Floor and ceiling effects, smallest detectable change (SDC95%) and minimal important change (MIC) were assessed to evaluate interpretability. RESULTS: The intraclass correlation coefficient for all 16 items was 0.89. For single items the test-retest kappa estimates ranged 0.38-0.85 and percent agreement 69-92%. Construct validity was acceptable with all six predefined hypotheses confirmed. Responsiveness was acceptable with 33 of 48 and three of four predefined hypotheses confirmed for single items and all items, respectively. There were no floor or ceiling effects. The SDC95% was 29.1 and 3.0 at the individual and group levels, respectively. MIC was 20.4. CONCLUSIONS: The OA-QI v2 had higher reliability estimates compared to v1, showed acceptable validity, and is the recommended version for future use. The results of responsiveness testing further support the use of the OA-QI v2 as an outcome measure in studies aiming to improve osteoarthritis care.

Little differences in digestive efficiency for protein and fat in mammals of different trophic guilds and digestive strategies: data constraints or fundamental functional similarity?

Carnivores do not vary markedly in their digestive efficiency for protein and fat, but whether they resemble other trophic guilds (omnivores and herbivores) in this respect has not been evaluated. We collated data on apparent crude protein (CP) and crude fat (ether extracts, EE) digestibility in 157 mammal species, applying the Lucas principle of regressing digestible nutrient content against nutrient content, where the slope of the regression equation represents the true digestibility and the intercept the metabolic losses per unit dry matter intake. The data collection is marked by the evident uneven distribution of dietary nutrient contents across trophic guilds and differences in the nutrient range by which different species have been evaluated, making statistical interpretation difficult. Results indicate a lower true digestibility of CP in herbivores compared to carnivores, most likely due to a lower digestibility of fibre-bound protein in herbivore diets. Metabolic CP losses did not appear to differ between trophic guilds, but herbivores had higher metabolic EE losses, compatible with the hypothesis that a higher proportion of metabolic CP losses were bound in microbes that also contain lipids in herbivores. Among herbivores, no clear pattern was evident that would indicate a difference in metabolic losses associated with microbes between digestive strategies (coprophagy, foregut/hindgut fermentation). Foregut fermenters had a lower true EE digestibility, possibly linked to the hydrogenation of lipids in their forestomach prior to digestion. The results do not demonstrate clear differences in digestive efficiency and metabolic losses for protein and fat between mammalian trophic guilds and digestive strategies, leading to the hypothesis that the process of CP and EE digestion is not physiologically challenging and hence does not lead to a noticeable differentiation between species or species groups.

Smoking and alcohol use are associated with structural and inflammatory hand osteoarthritis features.

OBJECTIVES: To explore whether smoking and alcohol use are associated with hand osteoarthritis (OA) features in two different OA cohorts. METHOD: We studied 530 people with radiographic hand OA from the Musculoskeletal pain in Ullensaker STudy (MUST) and 187 people from the Oslo hand OA cohort [mean (sd) age 65 (8.0) and 62 (5.7) years, 71% and 91% women, respectively]. Smoking, alcohol use and hand pain were self-reported. Participants underwent conventional hand radiographs and ultrasound examination of 30 hand joints. The Kellgren-Lawrence sum score for radiographic OA severity (0-120 scale) and the proportion of participants having at least one joint with grey-scale synovitis (grade ≥1) were calculated. We studied whether smoking and alcohol use were cross-sectionally associated with radiographic OA, synovitis, and pain using adjusted linear and logistic regression analyses. RESULTS: Smoking was associated with less radiographic OA in both cohorts [ß = -4.71, 95% confidence interval (CI) -8.36 to -1.06 for current smoking in MUST and ß = -0.15, 95% CI -0.29 to -0.02 for smoking pack-years in the Oslo hand OA cohort]. Stratified analyses indicated that the association was present in men only. Being a monthly drinker (examined in MUST only) was significantly associated with present synovitis compared to never drinkers (odds ratio = 2.35, 95% CI 1.27 to 4.34) (no gender differences). Neither smoking nor alcohol was associated with hand pain. CONCLUSIONS: Smoking was associated with less radiographic hand OA whereas alcohol consumption was associated with present joint inflammation in hand OA. Future longitudinal studies are needed to explore the causal associations and explanatory mechanisms behind gender differences.

Genetic factors contribute more to hip than knee surgery due to osteoarthritis - a population-based twin registry study of joint arthroplasty.

OBJECTIVE: To explore and quantify the relative strengths of the genetic contribution vs the contribution of modifiable environmental factors to severe osteoarthritis (OA) having progressed to total joint arthroplasty. DESIGN: Incident data from the Norwegian Arthroplasty Registry were linked with the Norwegian Twin Registry on the National ID-number in 2014 in a population-based prospective cohort study of same-sex twins born 1915-60 (53.4% females). Education level and height/weight were self-reported and Body Mass Index (BMI) calculated. The total follow-up time was 27 years for hip arthroplasty (1987-2014, 424,914 person-years) and 20 years for knee arthroplasty (1994-2014, 306,207 person-years). We estimated concordances and the genetic contribution to arthroplasty due to OA in separate analyses for the hip and knee joint. RESULTS: The population comprised N = 9058 twin pairs (N = 3803 monozygotic (MZ), N = 5226 dizygotic (DZ)). In total, 73% (95% confidence intervals (CI) = 66-78%) and 45% (95% CI = 30-58%) of the respective variation in hip and knee arthroplasty could be explained by genetic factors. Zygosity (as a proxy for genetic factors) was associated with hip arthroplasty concordance over time when adjusted for sex, age, education and BMI (HR = 2.98, 95% CI = 1.90-4.67 for MZ compared to DZ twins). Knee arthroplasty was to a greater extent dependent on BMI when adjusted for zygosity and the other covariates (HR = 1.15, 95% CI = 1.02-1.29). CONCLUSION: Hip arthroplasty was strongly influenced by genetic factors whereas knee arthroplasty to a greater extent depended on a high BMI. The study may imply there is a greater potential for preventing progression of knee OA to arthroplasty in comparison with hip OA.

Rasch analysis of the Norwegian version of the Arthritis Self-Efficacy Scale (ASES).

OBJECTIVES: To apply the Rasch model to the Norwegian version of the Arthritis Self-Efficacy Scale (ASES). METHOD: The ASES was included in a self-administered questionnaire sent to 224 patients attending one of three rehabilitation centres for rheumatic diseases in Norway in 2009. The fit of the ASES to the Rasch model was assessed together with hypothesized associations with the Modified Health Assessment Questionnaire (MHAQ), the 36-item Short Form Health Survey (SF-36), the numerical rating scale (NRS) for pain, and NRS fatigue. RESULTS: A total of 145 (64.7%) patients responded to the questionnaire. The two scales of other symptoms and pain showed good fit to the Rasch model with no evidence for differential item functioning (DIF) according to eight sociodemographic and disease-related variables. The Person Separation Index (PSI), which is equivalent to Cronbach's alpha, ranged from 0.74 to 0.78. Correlations with scores for other instruments were as hypothesized: ASES pain had the highest correlations with SF-36 pain and NRS pain and ASES other symptoms had the highest correlations with other aspects of the SF-36 and NRS fatigue. CONCLUSIONS: The ASES had good fit to the Rasch model and correlations with other instrument scores that followed hypotheses, lending further support to the application of the instrument in patients with rheumatic diseases.

Retention of solute and particle markers in the digestive tract of chinchillas (Chinchilla laniger).

The chinchilla (Chinchilla laniger) is a herbivorous hystricomorph South American rodent for which no mean digesta retention times have been reported so far. Six animals (mean body mass ± standard deviation: 513 ± 99 g) on a diet of grass hay and lucerne-based pellets were given a pulse dose of a solute (cobalt-EDTA) and a particle (chromium-mordanted fibre, <2 mm) marker with subsequent frequent faecal collection. Dry matter intake was 45.2 ± 8.0 g/kg(0.75) /day. Mean retention times were 22.2 ± 5.3 h for solutes and 25.4 ± 5.2 h for particles, with the difference being not significant within individuals. This indicates the presence of a 'mucus-trap' colonic separation mechanism, which is in accord with morphological descriptions of the typical colonic furrow in chinchillas. Corresponding to a strategy of colonic digesta separation and caecotroph formation, secondary marker excretion peaks indicated coprophagic events that were spaced approximately 12 h apart. Given that these retention times appear longer than measures reported for rabbits (Oryctolagus cuniculus) or guinea pigs (Cavia procellus), it would be interesting to compare the digestive efficiency of chinchillas on high levels of dietary fibre to other species.

Individual and joint effects of risk factors for onset widespread pain and obesity - a population-based prospective cohort study.

BACKGROUND: Widespread musculoskeletal pain (WSP) and obesity frequently co-occur and may have shared risk factors. We aimed to investigate whether four dichotomized risk factors individually or jointly increase the risk for the onset of WSP and onset of obesity. METHODS: Persons aged 34-76 years in 2004 living in Ullensaker municipality, Norway, responded to questionnaires in 2004 and 2010 (n = 1553). Using causal interaction analyses, we examined whether baseline obesity and WSP, poor sleep quality, mental distress and poor physical fitness jointly increased the risk of new onset WSP (≥3 pain sites leading to disability the last year) and new onset obesity (self-reported BMI ≥30 kg/m(2) ) in persons without WSP (n = 1270) or without obesity (n = 1300) at baseline respectively. RESULTS: The mean (SD) age was 51 (12.1) years and 56% were female. The incidence of WSP and obesity were 9.1% and 5.4%. Mental distress and poor sleep quality individually and jointly with poor physical fitness increased WSP onset risk (relative excess risk due to interaction [RERI] = 1.90, 95% CI, 0.39-3.42 and RERI = 1.43, 95% CI, 0.10-2.76). Poor physical fitness individually increased the risk for new onset obesity, and baseline WSP and poor sleep quality jointly (RERI = 1.87, 95% CI, 0.49-3.24). The presence of more risk factors was dose-dependently associated with onset WSP and to a lesser extent with onset obesity. CONCLUSION: The onset of WSP and the onset of obesity were results of joint effects of exposures. Poor physical fitness was a key covariate in increasing the risk for both conditions. WHAT DOES THIS STUDY ADD?: In a general population, the new onset of widespread pain and new onset of obesity were results of joint effects of risk factors and particularly poor physical fitness. The study may aid in the identification of patients at risk of future disability.

Self-reported quality care for knee osteoarthritis: comparisons across Denmark, Norway, Portugal and the UK.

OBJECTIVES: To assess and compare patient perceived quality of osteoarthritis (OA) management in primary healthcare in Denmark, Norway, Portugal and the UK. METHODS: Participants consulting with clinical signs and symptoms of knee OA were identified in 30 general practices and invited to complete a cross-sectional survey including quality indicators (QI) for OA care. A QI was considered as eligible if the participant had checked 'Yes' or 'No', and as achieved if the participant had checked 'Yes' to the indicator. The median percentage (with IQR and range) of eligible QIs achieved by country was determined and compared in negative binominal regression analysis. Achievement of individual QIs by country was determined and compared using logistic regression analyses. RESULTS: A total of 354 participants self-reported QI achievement. The median percentage of eligible QIs achieved (checked 'Yes') was 48% (IQR 28%, 64%; range 0-100%) for the total sample with relatively similar medians across three of four countries. Achievement rates on individual QIs showed a large variation ranging from 11% (referral to services for losing weight) to 67% (information about the importance of exercise) with significant differences in achievement rates between the countries. CONCLUSIONS: The results indicated a potential for improvement in OA care in all four countries, but for somewhat different aspects of OA care. By exploring these differences and comparing healthcare services, ideas may be generated on how the quality might be improved across nations. Larger studies are needed to confirm and further explore the findings.

Organic matter and macromineral digestibility in domestic rabbits (Oryctolagus cuniculus) as compared to other hindgut fermenters.

It is generally assumed that animal species differ in physiological characteristics of their digestive tract. Because investigating digestive processes is often labour-intensive, requiring lengthy adaptation and collection periods, comparisons are often made on the basis of data collated from different studies. We added a new data set on dietary crude fibre (CF) and macromineral (Na, K, Ca, P, Mg) composition and apparent digestibility (aD) of organic matter (OM) and macrominerals in rabbits (Oryctolagus cuniculus; a total of 180 measurements with 12 individuals and 10 different diets) to a literature data collection for rodents and domestic horses (Equus caballus). Significant negative relationships between dietary CF and aD OM were obtained, but the significant difference in digestive efficiency between rabbits and guinea pigs (Cavia porcellus) reported from studies where both species had been investigated under identical conditions were not detectable in the larger data collection. However, the 95% confidence interval of the negative slope of the CF-aD OM relationship did not overlap between domestic horses on the one hand, and rabbits and guinea pigs on the other hand, indicating a less depressing effect of CF in horses. Akaike's information criterion indicated that aD of a macromineral did not only depend on its concentration in the diet, but also on the individual and various other diet characteristics and the presence of other macrominerals, indicating complex interactions. The data indicate similar mechanisms in the absorption of macrominerals amongst rabbits, rodents and horses, with the exception of Na and K in guinea pigs and Ca in chinchillas (Chinchilla laniger) that should be further corroborated. In particular, the occurrence of high aD Ca in hindgut fermenters, regardless of whether they employ a digestive strategy of coprophagy or whether they have fossorial habits, suggests that this peculiarity might represent an adaptation to hindgut fermentation in general.

Body mass index and progressive hand osteoarthritis: data from the Oslo hand osteoarthritis cohort.

OBJECTIVES: Few longitudinal studies have studied the association between body mass index (BMI) and hand osteoarthritis (OA). We aimed to explore the association between BMI and progressive hand OA in a longitudinal study of the Oslo hand OA cohort. METHOD: Participants with existing hand OA had hand radiographs and BMI data taken at baseline and 7-year follow-up (n = 103). The radiographs were read according to the Kellgren-Lawrence (KL) scale. First, we examined the association between baseline BMI and incident OA (KL grade ≥ 2) in joints without OA at baseline (adjusted for age and sex) using generalized estimating equation (GEE) analyses. Second, we examined whether changes in BMI from baseline to follow-up were associated with increasing KL sum score from baseline to follow-up using linear regression. We repeated the analyses using changes in number of joints with symptomatic OA and patient-reported pain and physical function as the outcome. RESULTS: The mean (SD) age at baseline was 61.6 (5.6) years and 91 (94%) of the cohort were women. The mean (SD) BMI was 25.7 (4.0) kg/m(2) at baseline and the mean (SD) BMI change was 1.1 (2.0) kg/m(2). There was no relationship between baseline BMI and development of more joints with OA during follow-up. Similarly, there was no association between change in BMI and hand OA progression, increasing hand pain or disability. CONCLUSIONS: In the Oslo hand OA cohort, higher BMI was not related to hand OA progression.

Circulating levels of inflammatory cytokines and cytokine receptors in patients with ankylosing spondylitis: a cross-sectional comparative study.

OBJECTIVES: Insight into the most important inflammatory pathways in ankylosing spondylitis (AS) could be of importance in risk stratification and the development of treatment strategies. Therefore, we aimed to compare circulating levels of inflammatory biomarkers between AS patients and controls, and explore associations between these biomarkers and clinical measures of disease activity. METHOD: In a cross-sectional study, 143 AS patients were compared with 124 population controls. Blood samples were analysed by immunoassays for interleukin (IL)-6, IL-17a, IL-23, soluble tumour necrosis factor receptor 1 (sTNF-R1) and 2 (sTNF-R2), and osteoprotegerin (OPG). Disease activity was measured by the AS Disease Activity Score (ASDAS) and the Bath AS Disease Activity Index (BASDAI). RESULTS: Analysis of covariance (ANCOVA) demonstrated elevated plasma levels of sTNF-R1 [geometrical mean 0.94 (95% CI 0.88-1.00) vs. 0.83 (95% CI 0.78-0.89) ng/mL, p < 0.01] and OPG (2.3, 95% CI 2.1-2.4 vs. 2.0, 95% CI 1.9-2.2 ng/mL, p = 0.02) and, although not significant, of IL-23 (122, 95% CI 108-139 vs. 106, 95% CI 93-120 pg/mL, p = 0.07) in AS patients vs. CONTROLS: More AS patients had a high level of sTNF-R2 than controls (22 vs. 1, p < 0.01). No differences between the groups were seen for IL-6 and IL-17a. In patients, no significant associations were seen between inflammatory markers and disease activity measures after adjusting for personal characteristics. CONCLUSION: Significantly higher plasma levels of sTNF-R1, sTNF-R2, and OPG and numerically but non-significantly higher levels of IL-23 were found in AS patients compared to controls, indicating that these cytokines and cytokine receptors are important inflammatory pathways. Clinical measures of disease activity were not significantly correlated with circulating inflammatory markers.

Limited effects of exercises in people with hand osteoarthritis: results from a randomized controlled trial.

OBJECTIVE: To determine the clinical effectiveness of an exercise programme on self-reported hand activity performance in people with hand osteoarthritis (OA). DESIGN: In this randomized, controlled trial, participants with physician-confirmed hand OA were randomly allocated to a 12-week exercise intervention (group- and home-based) or usual care. The primary outcome was self-reported hand activity performance at 3 months measured by the Functional Index for Hand Osteoarthritis (FIHOA) and a patient-generated measure of disability, the Patient-Specific Functional Scale (PSFS). RESULTS: Of 130 randomized participants (mean age 66 (standard deviation (SD) 9); female 90%), 120 (92%) and 119 (92%) completed the 3- and 6-month follow-ups. The adjusted mean difference for the exercise vs control group was -0.5 points (95% confidence interval (CI) -1.6, 0.6) for the FIHOA score (0-30 scale, 0 = best) and 0.9 points (95% CI 0.1, 1.7) for the PSFS score (0-10 scale, 10 = best). Small significant mean differences in favour of the intervention group were found for hand pain, hand stiffness and disease activity, whereas no mean differences were observed in hand dexterity or maximal grip strength. A significantly larger proportion in the intervention (46%) vs control group (16%) fulfilled the Outcome Measures in Rheumatological Clinical Trials-Osteoarthritis Research Society International (OMERACT-OARSI) responder criteria at 3 months (OR = 4.4, 95% CI 1.9, 10.2). At the 6-month follow-up, there were no significant group differences in any outcome. CONCLUSIONS: The exercise programme was well tolerated among people with hand OA, but resulted only in small, beneficial short-term improvements on self-reported measures and not on most performance-based tests. Future studies should address optimal grip strength exercises and dosage. TRIAL REGISTRATION: ClinicalTrials.gov registration number: NCT01245842.

No strong relationship between body mass index and clinical hand osteoarthritis: results from a population-based case-control study.

OBJECTIVES: The aim of this population-based case-control study was to investigate whether a high body mass index (BMI) is a risk factor for clinical hand osteoarthritis (OA). METHOD: Persons living in Ullensaker municipality in Norway who were aged 20-52 years in 1990 reported height and weight in 1990, 1994, 2004, and 2010 (n = 1276). Cases (clinical hand OA in 2010, n = 59) were compared to controls (participants without self-reported OA or hand pain in 2010, n = 805) with regard to the prospectively measured BMI by means of a generalized estimating equation (GEE) analysis adjusted for age, sex, time, and education. RESULTS: The mean age of hand OA cases was 64 (SD = 7.5) years in 2010 and 78% were women. There was no association between total average BMI over the entire period and later clinical hand OA (p = 0.320). Cases had a higher mean BMI in 1990 [unstandardized B = 0.93, 95% confidence interval (CI) 0.07-1.79] and in 1994 (B = 0.75, 95% CI 0.22-1.28) but there were no differences between the groups in 2004 or 2010. CONCLUSIONS: The study lend support to the hypothesis that having a higher BMI when young or middle-aged might be associated with later hand OA.

No strong temporal relationship between obesity and multisite pain--results from a population-based 20-year follow-up study.

BACKGROUND: Multisite pain and obesity are cross-sectionally related and are common conditions that may influence each other through socio-demographic, lifestyle and/or health-related factors. The aim of the present study was to examine the cross-sectional and prospective associations between overweight/obesity and multisite pain in a general population. METHODS: In a 20-year population-based prospective cohort study, persons aged 20-62 years in 1990 participated in postal surveys in 1990, 1994, 2004 and 2010 (n = 855). Multisite pain was defined as reporting ≥ 2 number of pain sites (NPS) on the Standardized Nordic Questionnaire. Overweight was defined as body mass index (BMI) 25-30 kg/m(2) and obesity as BMI ≥ 30 kg/m(2). To exploit all measurement times, generalized estimating equation analyses adjusting for age, sex, educational and occupational status, smoking, sleep quality, mental distress and physical activity were employed. RESULTS: The mean age was 41 years at baseline and 57% were women. Overweight/obesity and NPS were significantly associated cross-sectionally. Being overweight/obese was associated with reporting future NPS ≥ 2 [overweight: odds ratio (OR), 1.40, 95% confidence interval (CI), 1.12-1.75, obese: OR, 1.54, 95% CI, 1.04-2.28]. Having NPS ≥ 2 was not associated with becoming overweight, but increased the OR for future obesity (OR 1.27, 95% CI, 1.02, 1.59). Smoking was a confounder in this relationship. CONCLUSIONS: Being overweight or obese was associated with future multisite pain, although the magnitude of the association was small and the dose-response relationship observed in cross-sectional analyses disappeared in prospective analyses. There was less evidence that having multisite pain was a predictor of future overweight/obesity.

Does the content really matter? A study comparing structure, process, and outcome of team rehabilitation for patients with inflammatory arthritis in two different clinical settings.

OBJECTIVES: To provide a thorough description of team rehabilitation care and compare the structure, process, and outcomes in two specialized arthritis rehabilitation settings. METHODS: Patients with inflammatory arthritis scheduled for inpatient rehabilitation in seven specialized rehabilitation centres and three rheumatology hospital departments in Norway were included consecutively in a prospective cohort study. Patients completed questionnaires at admission, at discharge, and at a 6-month follow-up, and kept a diary regarding structure and process variables during the rehabilitation stay. RESULTS: Eighty patients in rehabilitation centres and 73 in hospital departments were included and 80% responded to the 6-month follow-up questionnaire. The two clinical settings differed significantly with regard to structure variables such as cost, referral of patients, length of stay, and number of health professionals involved, and most process variables reflecting treatment modalities. The most remarkable difference was in the amount of individual intervention compared with group intervention. Despite significant improvements in most outcomes at discharge, the scores deteriorated towards baseline level 6 months later. There was a trend towards more significant improvement during rehabilitation for patients at rehabilitation centres whereas patients at hospitals had more prolonged improvement. CONCLUSIONS: Team rehabilitation for inflammatory arthritis in two different clinical settings differed across most variables for structure and process, but few significant differences in outcome were found. Considering the substantial differences in cost, there is an urgent need for consensus concerning which patients should receive rehabilitation in which setting. Future research on the development and evaluation of methods for prolonging the beneficial effects of rehabilitation is needed.

Perceived functional ability assessed with the spinal function sort: is it valid for European rehabilitation settings in patients with non-specific non-acute low back pain?

The aim of this study involving 170 patients suffering from non-specific low back pain was to test the validity of the spinal function sort (SFS) in a European rehabilitation setting. The SFS, a picture-based questionnaire, assesses perceived functional ability of work tasks involving the spine. All measurements were taken by a blinded research assistant; work status was assessed with questionnaires. Our study demonstrated a high internal consistency shown by a Cronbach's alpha of 0.98, reasonable evidence for unidimensionality, spearman correlations of >0.6 with work activities, and discriminating power for work status at 3 and 12 months by ROC curve analysis (area under curve = 0.760 (95% CI 0.689-0.822), respectively, 0.801 (95% CI 0.731-0.859). The standardised response mean within the two treatment groups was 0.18 and -0.31. As a result, we conclude that the perceived functional ability for work tasks can be validly assessed with the SFS in a European rehabilitation setting in patients with non-specific low back pain, and is predictive for future work status.

Patient experiences of rehabilitation in rheumatology: association with process and outcome.

OBJECTIVE: To evaluate health-care experiences of patients following inpatient rheumatology rehabilitation and to assess the association between these experiences and aspects of health-care delivery and patient characteristics. METHODS: Data were collected from 435 patients with a rehabilitation stay of >or= 1 week at 12 institutions in Norway in 2006. At discharge, patients completed the Rehabilitation Patient Experiences Questionnaire (Re-PEQ), which includes four important aspects of patient experiences. Multiple regression analysis was used to assess associations between Re-PEQ scores, health-care process, health and sociodemographic variables. RESULTS: A total of 412 (94.7%) patients completed the Re-PEQ; scores ranged from 69 (social environment) to 83 (care/organization) on the 0-100 scale, where 100 represents the best possible experience. The social environment scale had the largest component of variation explained by the independent variables, which included number of doctor visits, amount of group education, and individual exercise (p < 0.01). The type of institution, number of doctor visits, mental health, and gender also explained significant components of variation in the other Re-PEQ scale scores. CONCLUSION: Patients reported good experiences with rheumatology rehabilitation. Areas where poorer experiences emerged can help target areas for future initiatives aimed at improving the quality of care. Health and sociodemographic variables should be controlled for in studies of patient experiences.