Predictors of outcome in patients with (sub) acute low back pain differ across treatment groups

Study Design. Prospective study with 6 weeks of follow-up. Objective. To examine the predictors of outcome for patients with (sub) acute low back pain (LBP) receiving usual care (UC) or a minimal intervention strategy (MIS) aimed at psychosocial factors. Summary of Background Data. A randomized controlled trial in general practice showed no differences in average effect between UC and MIS. Methods. Socio-demographic variables, characteristics of LBP, and psychosocial factors were included as potential predictors of outcome. The outcome clinically important improvement was defined as a reduction of at least 30% on functional disability plus patient perceived recovery. Logistic regression analyses were used to study the associations between predictors and outcome at 6 weeks follow-up. Results. In the UC group (n = 163), the multivariable model included a shorter duration of the LBP episode, few previous episodes, less pain catastrophizing, and good perceived general health. The area under the curve (AUC) of the model was 0.77 (95% confidence interval, 0.70-0.85). In the MIS group (n = 142), the multivariable model included less somatizing symptoms, more solicitous responses by an important other, lower perceived risk for chronic LBP, more fear avoidance beliefs, higher level of education, and shorter duration of the LBP episode. This AUC was 0.78 (95% confidence interval, 0.71-0.86). Conclusions. As we found two different profiles, our approach may contribute to the important question: what intervention works for whom

Should treatment of (sub)acute low back pain be aimed at psychosocial prognostic factors? Cluster randomised clinical trial in general practice

OBJECTIVE: To compare the effects of a minimal intervention strategy aimed at assessment and modification of psychosocial prognostic factors and usual care for treatment of (sub)acute low back pain in general practice. DESIGN: Cluster randomised clinical trial. SETTING: 60 general practitioners in 41 general practices. PARTICIPANTS: 314 patients with non-specific low back pain of less than 12 weeks' duration, recruited by their general practitioner. INTERVENTIONS: In the minimal intervention strategy group the general practitioner explored the presence of psychosocial prognostic factors, discussed these factors, set specific goals for reactivation, and provided an educational booklet. The consultation took about 20 minutes. Usual care was not standardised. MAIN OUTCOME MEASURES: Functional disability (Roland-Morris disability questionnaire), perceived recovery, and sick leave because of low back pain assessed at baseline and after 6, 13, 26, and 52 weeks. RESULTS: The dropout rate was 8% in the minimal intervention strategy group and 9% in the usual care group. Multilevel analyses showed no significant differences between the groups on any outcome measure during 12 months of follow-up in the whole group or in relevant subgroups (patients with high scores on psychosocial measures at baseline or a history of frequent or prolonged low back pain). CONCLUSION: This study provides no evidence that (Dutch) general practitioners should adopt our new treatment strategy aimed at psychosocial prognostic factors in patients with (sub)acute low back pain. Further research should examine why our new strategy was not more effective than usual car

Effects of ultrafine particles on the allergic inflammation in the lung of asthmatics : results of a double-blinded randomized cross-over clinical pilot study

Background: Epidemiological and experimental studies suggest that exposure to ultrafine particles (UFP) might aggravate the allergic inflammation of the lung in asthmatics. Methods: We exposed 12 allergic asthmatics in two subgroups in a double-blinded randomized cross-over design, first to freshly generated ultrafine carbon particles (64 μg/m3; 6.1 ± 0.4 × 105 particles/cm3 for 2 h) and then to filtered air or vice versa with a 28-day recovery period in-between. Eighteen hours after each exposure, grass pollen was instilled into a lung lobe via bronchoscopy. Another 24 hours later, inflammatory cells were collected by means of bronchoalveolar lavage (BAL). (Trial registration: NCT00527462) Results: For the entire study group, inhalation of UFP by itself had no significant effect on the allergen induced inflammatory response measured with total cell count as compared to exposure with filtered air (p = 0.188). However, the subgroup of subjects, which inhaled UFP during the first exposure, exhibited a significant increase in total BAL cells (p = 0.021), eosinophils (p = 0.031) and monocytes (p = 0.013) after filtered air exposure and subsequent allergen challenge 28 days later. Additionally, the potential of BAL cells to generate oxidant radicals was significantly elevated at that time point. The subgroup that was exposed first to filtered air and 28 days later to UFP did not reveal differences between sessions. Conclusions: Our data demonstrate that pre-allergen exposure to UFP had no acute effect on the allergic inflammation. However, the subgroup analysis lead to the speculation that inhaled UFP particles might have a long-term effect on the inflammatory course in asthmatic patients. This should be reconfirmed in further studies with an appropriate study design and sufficient number of subjects

General practitioners apply the usual care for shoulder complaints better than expected – analysis of videotaped consultations

BACKGROUND: The education and activation program (EAP) is a newly developed intervention to prevent the development of chronic shoulder complaints (SCs). Trained general practitioners (GPs) administer the EAP. The EAP addresses inadequate cognitions and maladaptive behavior related to the SCs. The effect of the EAP is evaluated in a randomized clinical trial. The aim of the present study is to use videotaped consultations to study (1) the performance of trained GPs administering the EAP and (2) the presence of key features of the EAP already embedded in usual care (UC). METHODS: Five trained GPs were videotaped while treating a standardized patient with EAP. Additionally, five GPs administering UC were videotaped. Two blinded observers evaluated the videotapes in relation to key features of the EAP which were scored on the EAP checklist. RESULTS: The mean total score on the EAP checklist was 4.7 (SD = 2.9) for the UC group and 7.1 (SD = 2.1) for the EAP group. Neither group reached a score higher than 8, which was considered to reflect an acceptable number of key EAP features. CONCLUSION: Our comparison of the presence of key features of EAP shows that the UC and EAP groups differed less than was expected. GPs in the UC group performed above expectation, with a mean total score of 4.7. Moreover, the low number of key features present in the EAP group may very well have led to a reduced effectiveness of the EAP. The results of this study can be used to optimize the training of GPs using the EAP

The search for stable prognostic models in multiple imputed data sets

<p>Abstract</p> <p>Background</p> <p>In prognostic studies model instability and missing data can be troubling factors. Proposed methods for handling these situations are bootstrapping (B) and Multiple imputation (MI). The authors examined the influence of these methods on model composition.</p> <p>Methods</p> <p>Models were constructed using a cohort of 587 patients consulting between January 2001 and January 2003 with a shoulder problem in general practice in the Netherlands (the Dutch Shoulder Study). Outcome measures were persistent shoulder disability and persistent shoulder pain. Potential predictors included socio-demographic variables, characteristics of the pain problem, physical activity and psychosocial factors. Model composition and performance (calibration and discrimination) were assessed for models using a complete case analysis, MI, bootstrapping or both MI and bootstrapping.</p> <p>Results</p> <p>Results showed that model composition varied between models as a result of how missing data was handled and that bootstrapping provided additional information on the stability of the selected prognostic model.</p> <p>Conclusion</p> <p>In prognostic modeling missing data needs to be handled by MI and bootstrap model selection is advised in order to provide information on model stability.</p

Evaluation of the measurement properties of the Manchester foot pain and disability index

BACKGROUND: The Manchester Foot Pain and Disability Index (MFPDI, 19 items) was developed to measure functional limitations, pain and appearance for patients with foot pain and is frequently used in both observational studies and randomised controlled trials. A Dutch version of the MFPDI was developed. The aims of this study were to evaluate all the measurement properties for the Dutch version of the MFPDI and to evaluate comparability to the original version. METHOD: The MFPDI was translated into Dutch using a forward/backward translation process. The dimensionality was evaluated using exploratory and confirmatory factor analysis. Measurement properties were evaluated per subscale according to the COSMIN taxonomy consisting of: reliability (internal consistency, test-retest reliability and measurement error), validity (structural validity, content validity and cross-cultural validity comparing the Dutch version to the English version) responsiveness and interpretation. RESULTS: The questionnaire consists of three scales, measuring foot function, foot pain and perception. The reliability of the foot function scale is acceptable (Cronbach’s α > 0.7, ICC = 0.7, SEM = 2.2 on 0-18 scale). The construct validity of the function and pain scale was confirmed and only the pain scale contains one item with differential item functioning (DIF). The responsiveness of the function and pain scale is moderate when compared to anchor questions. CONCLUSION: Results using the Dutch MFPDI version can be compared to results using the original version. The foot function sub-scale (items 1-9) is a reliable and valid sub-scale. This study indicates that the use of the MFPDI as a longitudinal instrument might be problematic for measuring change in musculoskeletal foot pain due to moderate responsiveness