A Prospective Cohort Study of the Impact of Return-to-Work Coordinators in Getting Injured Workers Back on the Job

Purpose To assess the impact of workplace-based return-to-work (RTW) Coordinators’ interpersonal and functional activities on RTW outcomes. Methods Multivariable logistic regression analyses of cross-sectional and longitudinal survey responses of 632 injured workers with at least 10 days of work absence in Victoria, Australia, adjusting for demographic and other workplace factors. Outcome was being back at work for at least 1 month, measured at both baseline and 6 month follow-up survey. Participant responses to stressfulness of Coordinator interactions were dichotomised into good and poor and evaluated as a proxy for Coordinators’ interpersonal activities, while having a RTW plan was evaluated as a proxy for functional activities. Results At baseline, RTW plans doubled the odds of RTW (OR 2.02; 95% CI 1.40–2.90) and attenuated the impact of good Coordinator interactions (1.14; 0.77–1.70). At 6-month follow-up, the opposite was observed: good interactions nearly doubled odds of RTW (1.90; 1.22–2.95) while RTW plans were non-significant (1.02; 0.68–1.54). Conclusions Differences between when the two Coordinator activities were effective may be due to the nature of claimants who RTW in each survey period. Length of shorter-duration claims are influenced by injury related factors, while psychosocial factors tend to be more important for longer-duration claims. Such factors may determine whether a claimant is more likely to respond to Coordinators’ functional or interpersonal activities. The findings have important implications for increasing Coordinator effectiveness.     

Implementing evidence-based guidelines for radiography in acute low back pain: a pilot study in a chiropractic community

OBJECTIVE: To evaluate the ability of a systematic educational intervention strategy to change the plain radiography ordering behavior of chiropractors toward evidence-based practice for patients with acute low back pain (LBP). DESIGN: A quasi-experimental method was used comparing outcomes before and after the intervention with those of a control community. SETTING: Two communities in southern Ontario. DATA SOURCE: Mailed survey data on the management of acute LBP.Outcome Measures Plain radiography use rates for acute LBP based on responses to mailed surveys. RESULTS: Following the intervention, there was a 42% reduction in the self-report need for plain radiography for uncomplicated acute LBP (P <.025) and a 50% reduction for patients with acute LBP < 1 month (P <.025) in the intervention community. There was no significant change in the self-report need for plain radiography in the control community (P >.05). CONCLUSIONS: The educational intervention strategy used in this study appeared to have an effect in reducing the perceived need for plain radiography in acute LBP.     

Multivariate, longitudinal analysis of the impact of changes in office work environments on surface electromyography measures

Purpose

To detect impacts of changes in work environment and worker-equipment interface variables upon surface electromyography (EMG) measures using multivariate, longitudinal analysis.

Methods

For 33 office workers, yearly measurements (1999–2001) were taken during normal work. Independent variables were related to work environment (expert-observed equipment dimensions, work organization on questionnaire) and interface (expert-observed postures, self-reported workstation-equipment relative fit i.e. inside or outside guidelines-informed location, and 30?min video-based task analysis). Internal mechanical exposure (EMG) was recorded bilaterally from extensor carpi radialis brevis (ECRB) and upper trapezius sites, each side, also for 30?min. Dependent variables were amplitude probability distribution functions (APDF 50 and 90%) and gaptime for entire record EMG (over all tasks) and task-specific EMG (for four separate tasks). Multivariate mixed models used independent variables to predict EMG measures (4 muscle sites?×?(1 entire record?+?4 task specific)?=?20 models total).

Results

Among EMG measures, 9/16 means and 2/16 variances were significantly different across years (p?Conclusion Longitudinal analysis with multivariate models can detect the impacts of changes in environment and interface exposures on EMG measures among office workers.     

Comparing Current Definitions of Return to Work: A Measurement Approach

Introduction Return-to-work (RTW) status is an often used outcome in work and health research. In low back pain, work is regarded as a normal activity a worker should return to in order to fully recover. Comparing outcomes across studies and even jurisdictions using different definitions of RTW can be challenging for readers in general and when performing a systematic review in particular. In this study, the measurement properties of previously defined RTW outcomes were examined with data from two studies from two countries. Methods Data on RTW in low back pain (LBP) from the Canadian Early Claimant Cohort (ECC); a workers?? compensation based study, and the Dutch Amsterdam Sherbrooke Evaluation (ASE) study were analyzed. Correlations between outcomes, differences in predictive validity when using different outcomes and construct validity when comparing outcomes to a functional status outcome were analyzed. Results In the ECC all definitions were highly correlated and performed similarly in predictive validity. When compared to functional status, RTW definitions in the ECC study performed fair to good on all time points. In the ASE study all definitions were highly correlated and performed similarly in predictive validity. The RTW definitions, however, failed to compare or compared poorly with functional status. Only one definition compared fairly on one time point. Conclusions Differently defined outcomes are highly correlated, give similar results in prediction, but seem to differ in construct validity when compared to functional status depending on societal context or possibly birth cohort. Comparison of studies using different RTW definitions appears valid as long as RTW status is not considered as a measure of functional status.     

Polysomnography in obese children with a history of sleep-associated breathing disorders

We hypothesized that obese children with a history of breathing difficulty during sleep would demonstrate (1) evidence of complete and partial obstructive sleep apnea (OSA) with hypercarbia and/or hypoxemia; and (2) correlation between symptoms, degree of obesity, adenoid and tonsil size, and polysomnography (PSG) results. We evaluated 32 obese children [% ideal body weight (IBW), 196±45%] with a sleep history questionnaire, airway radiographs, electrocardiograms (ECG), and PSG. By history, we found snoring (100%), difficulty breathing (59%), sweating (44%). restlessness (53%), arousals (41%), apnea (50%), worsening with upper respiratory infection (URI) (81%), hypersomnolence (59%), and mouth breathing (59%). We found adenoid and/or tonsil enlargement on 75% of airway x-ray pictures. ECGs were abnormal in 5 patients. Among all patients, mean sleep study oxyhemoglobin saturation (SaO₂) was 85±16% and mean end-tidal CO₂ (PetCO₂ ) was 51±7 torr; 84% had paradoxical inward movement of the chest on inspiration, 59% had OSA, and 66% had partial OSA. In those with ?200% IBW and adenotonsillar enlargement, elevated PetCO₂ and the presence of hypoxemia (SaO₂<90%) for ?5% of the total sleep time (TST) were correlated, unlike in patients of similar weight but without adenotonsillar enlargement. Individual symptoms did not correlate with the severity of PSG abnormalities. By discriminant analysis, using three variables (IBW, presence of adenotonsillar tissue, and presence of ?5 symptoms), we could predict PSG abnormalities with up to 81% reliability. Our findings indicate that in obese children, particularly those with %IBW ?200 and adenotonsillar hypertrophy, with sleep-disordered breathing evaluation by polysomnography should be considered. Pediatr Pulmonol. 1993; 16:124–129. © 1993 Wiley-Liss, Inc.     

Prognosis in soft tissue disorders of the shoulder: predicting both change in disability and level of disability after treatment

BACKGROUND AND PURPOSE: Clinicians often are faced with questions about prognosis and outcome of shoulder disorders. The purpose of this study was to identify predictors of both change in disability and level of disability following physical therapy treatment. SUBJECTS: The subjects were consecutive patients (n=361) who were receiving physical therapy for soft tissue shoulder disorders. METHODS: Clinical response to physical therapy, which was measured using the Disabilities of the Arm, Shoulder, and Hand (DASH) measure, was assessed over 12 weeks. The 28 independent baseline predictors included demographics, disorder-related and disability measures, medication use, clinical findings, and expectations for recovery. Multiple linear regression techniques were used. RESULTS: Predictors of greater disability at discharge were: higher initial disability, therapist prediction of restricted activities at discharge, workers' compensation claim, older age, and being female. Predictors of greater improvement in disability were: shoulder surgery, higher pain intensity, shorter duration of symptoms, younger age, and poorer general physical health (measured using the 36-Item Short-Form Health Survey [SF-36]). DISCUSSION AND CONCLUSIONS: Prognostic factors differ depending on the format of the outcome. Only age was significant in both models.     

Unipolar Sensing in Contemporary Pacemakers: Using Myopotential Testing to Define Optimal Sensitivity Settings

Bipolar lead use has increased due to oversensing concerns with older unipolar systems. Data on contemporary unipolar devices with improved hardware design and greater programming flexibility is lacking. Using a randomized crossover design, unipolar and bipolar sensing characteristics of 22 atrial and 16 ventricular leads were compared in 34 patients who had pulse generators of programmable polarity.Unipolar and bipolar intracardiac electrogram amplitudes, pacing and sensing thresholds at rest were similar. Provocative maneuvers were used to assess for myopotential inhibition. At atrial sensitivities of 0.625–1.50 mV, myopotential inhibition occurred in 11 (50%) atrial leads in the unipolar mode compared to 1 (5%) in the bipolar mode (p &lt; 0.001). At sensitivities of &gt;1.50 mV myopotential inhibition occurred in only 1 ventricular (unipolar) lead. An optimal sensitivity setting for each polarity was derived using clinic test results and assessed by ambulatory ECG (AECG). At these optimal settings, oversensing occurred in 1 (6%) atrial and 1 (8%) ventricular unipolar lead during AECG monitoring, whereas oversensing was not seen in any leads programmed to the bipolar mode. Undersensing occurred in 5 (29%) atrial unipolar versus 1 (6%) bipolar lead (p &equals; 0.08). Undersensing was not observed in any of the ventricular leads.Myopotential inhibition may be frequently provoked by provocative maneuvers at higher sensitivity settings in atrial unipolar leads. The frequency of oversensing can be significantly reduced by defining an optimal sensitivity setting using simple isometric maneuvers. Given present day concerns over bipolar lead longevity, increased utilization of unipolar ventricular leads should be considered.     

Understanding recovery: Changes in the relationships of the International Classification of Functioning (ICF) components over time

The International Classification of Functioning, Disability and Health framework describes human functioning through body structure and function, activity and participation in the context of a person's social and physical environment. This work tested the temporal relationships of these components. Our hypotheses were: 1) there would be associations among physical impairment, activity limitations and participation restrictions within time; 2) prior status of a component would be associated with future status; 3) prior status of one component would influence status of a second component (e.g. prior activity limitations would be associated with current participation restrictions); and, 4) the magnitude of the within time relationships of the components would vary over time. Participants from Canada with primary hip or knee joint replacement (n = 931), an intervention with predictable improvement in pain and disability, completed standardized outcome measures pre-surgery and five times in the first year post-surgery. These included physical impairment (pain), activity limitations and participation restrictions. ICF component relationships were evaluated cross-sectionally and longitudinally using path analysis adjusting for age, sex, BMI, hip vs. knee, low back pain and mood. All component scores improved significantly over time. The path coefficients supported the hypotheses in that both within and across time, physical impairment was associated with activity limitation and activity limitation was associated with participation restriction; prior status and change in a component were associated with current status in another component; and, the magnitude of the path coefficients varied over time with stronger associations among components to three months post surgery than later in recovery with the exception of the association between impairment and participation restrictions which was of similar magnitude at all times. This work enhances understanding of the complexities of the ICF component relationships in evaluating disability over time. Further longitudinal studies including evaluation of contextual factors are required.