Publications

BACKGROUND

Hospital workers are at high risk of work-related musculoskeletal disorders (WRMSDs), but outcomes following such injuries have not been well studied longitudinally.

AIMS

To ascertain functional recovery in hospital workers following incident WRMSDs and identify predictors of functional status.

METHODS

Cases (incident WRMSD) and matched referents from two hospitals were studied at baseline and at 2 year follow-up for health status [SF-12 physical component summary (PCS)], lost workdays, self-rated work effectiveness and work status change (job change or work cessation). Predictors included WRMSD and baseline demographics, socio-economic status (SES), job-related strain and effort-reward imbalance. Logistic regression analysis tested longitudinal predictors of adverse functional status.

RESULTS

The WRMSD-associated risk of poor (lowest quartile) PCS was attenuated from a baseline odds ratio (OR) of 5.2 [95% confidence interval (CI) 3.5-7.5] to a follow-up OR of 1.5 (95% CI 1.0-2.3) and was reduced further in multivariate modelling (OR = 1.4; 95% CI 0.9-2.2). At follow-up, WRMSD status did not predict significantly increased likelihood of lost workdays, decreased effectiveness or work status change. In multivariate modelling, lowest quintile SES predicted poor PCS (OR = 2.0; 95% CI 1.0-4.0) and work status change (OR = 2.5; 95% CI 1.1-5.8). High combined baseline job strain/effort-reward imbalance predicted poor PCS (OR = 1.7; 95% CI 1.1-2.7) and reduced work effectiveness (OR = 2.6; 95% CI 1.6-4.2) at follow-up.

CONCLUSIONS

Baseline functional deficits associated with incident WRMSDs were largely resolved by 2 year follow-up. Nonetheless, lower SES and higher combined job strain/effort-reward imbalance predicted adverse outcomes, controlling for WRMSDs.

AIMS

Individuals with asthma may be at increased risk of depression, but few studies have identified precursors to the onset of depression. The study goal was to identify risk factors for depression onset among a community-based sample of adults with asthma.

METHODS

Data were obtained from three telephone interviews conducted at 2-yearly intervals on a longitudinal cohort of adults with asthma (n=439). The Center for Epidemiologic Studies Depression scale (CESD) was used to measure depressive symptoms. Multiple regression analyses tested associations of sociodemographic and health-related variables with depression prevalence (cross-sectional analyses) and incident depression (longitudinal analyses).

RESULTS

15% of subjects were classified as "depressed" (CESD> or =23) at each interview. Individuals depressed at baseline were more likely to drop out (OR=1.76 [95% CI 1.05, 2.96]). Low perceived control of asthma (measured with the Perceived Control of Asthma Questionnaire [PCAQ]) exhibited the most consistent association with depression. Lower PCAQ was cross-sectionally associated with depression (OR=0.51 per 0.5 SD difference in PCAQ [0.35, 0.75]). Onset of depression was noted in 38 individuals. Decrease in perceived control at follow-up was associated with depression onset (OR=7.47 [2.15, 26.01]).

CONCLUSIONS

Low perceived control of asthma predicted depression onset among adults with asthma. This risk factor may respond to self-management education.

BACKGROUND

several studies have shown an association between chronic obstructive pulmonary disease (COPD) and cognitive impairment. These studies have been limited by methodological issues such as diagnostic uncertainty, cross-sectional design, small sample size, or lack of appropriate referent group. This study aimed to elucidate the association between COPD and the risk of cognitive impairment compared to referent subjects without COPD. In patients with established COPD, we evaluated the impact of disease severity and impairment of respiratory physiology on cognitive impairment and the potential mitigating role of oxygen therapy.

METHODS

we used the Function, Living, Outcomes and Work (FLOW) cohort study of adults with COPD (n = 1202) and referent subjects matched by age, sex, and race (n = 302) to study the potential risk factors for cognitive impairment among subjects with COPD. Cognitive impairment was defined as a Mini-Mental State Exam score of <24 points. Disease severity was using Forced Expiratory Volume in one second (FEV(1)); the validated COPD Severity Score; and the BMI (Body Mass Index), Obstruction, Dyspnea, Exercise Capacity (BODE) Index. Multivariable analysis was used to control for confounding by age, sex, race, educational attainment, and cigarette smoking.

RESULTS

COPD was associated with a substantive risk of cognitive impairment compared to referent subjects (odds ratio [OR] 2.42; 95% confidence interval [CI] 1.043-6.64). Among COPD patients, none of the COPD severity measures were associated with the risk of cognitive impairment (P > 0.20 in all cases). Low baseline oxygen saturation was related to increased risk of cognitive impairment (OR for oxygen saturation ≤88% (OR 5.45; 95% CI 1.014-29.2; P = 0.048). Conversely, regular use of supplemental oxygen therapy decreased the risk for cognitive impairment (OR 0.14; 95% CI 0.07-0.27; P < 0.0001).

CONCLUSION

COPD is a major risk factor for cognitive impairment. Among patients with COPD, hypoxemia is a major contributor and regular use of home oxygen is protective. Health care providers should consider screening their COPD patients for cognitive impairment.

BACKGROUND

COPD is a major cause of disability, but little is known about how disability develops in this condition.

METHODS

The authors analysed data from the Function, Living, Outcomes and Work (FLOW) Study which enrolled 1202 Kaiser Permanente Northern California members with COPD at baseline and re-evaluated 1051 subjects at 2-year follow-up. The authors tested the specific hypothesis that the development of specific non-respiratory impairments (abnormal body composition and muscle strength) and functional limitations (decreased lower extremity function, poor balance, mobility-related dyspnoea, reduced exercise performance and decreased cognitive function) will determine the risk of disability in COPD, after controlling for respiratory impairment (FEV(1) and oxygen saturation). The Valued Life Activities Scale was used to assess disability in terms of a broad range of daily activities. The primary disability outcome measure was defined as an increase in the proportion of activities that cannot be performed of 3.3% or greater from baseline to 2-year follow-up (the estimated minimal important difference). Multivariable logistic regression was used for analysis.

RESULTS

Respiratory impairment measures were related to an increased prospective risk of disability (multivariate OR 1.75; 95% CI 1.26 to 2.44 for 1 litre decrement of FEV(1) and OR 1.57 per 5% decrement in oxygen saturation; 95% CI 1.13 to 2.18). Non-respiratory impairment (body composition and lower extremity muscle strength) and functional limitations (lower extremity function, exercise performance, and mobility-related dyspnoea) were all associated with an increased longitudinal risk of disability after controlling for respiratory impairment (p<0.05 in all cases). Non-respiratory impairment and functional limitations were predictive of prospective disability, above-and-beyond sociodemographic characteristics, smoking status and respiratory impairment (area under the receiver operating characteristic curve increased from 0.65 to 0.75; p<0.001).

CONCLUSIONS

Development of non-respiratory impairment and functional limitations, which reflect the systemic nature of COPD, appear to be critical determinants of disablement. Prevention and treatment of disability require a comprehensive approach to the COPD patient.

BACKGROUND

Separate health-related quality of life (HRQL) instruments exist for asthma and rhinitis. The Rhinasthma questionnaire, originally developed in Italian, is a unique measure designed for use where both conditions coexist.

OBJECTIVE

We sought to assess the performance and validity of a new adaptation of the Rhinasthma questionnaire for use in English-speaking populations.

METHODS

We analyzed cross-sectional data from an ongoing study of adults with asthma and rhinitis (n = 450), asthma alone (n = 75), or rhinitis alone (n = 20). Subjects were administered an English translation of the original 30-item Rhinasthma questionnaire. Health status measures simultaneously assessed include the Short Form (SF)-12, EuroQol (EQ)-5D, and Marks Asthma Quality-of-Life.

RESULTS

Variable cluster analysis of the original 30-item instrument identified 5 discrete item clusters corresponding to the following domains: nasal (5 items), eye (4 items), respiratory (5 items), activity restriction (9 items), and treatment burden (5 items). Two other items were removed because of poor item-cluster correlations. Subjects with concomitant asthma and rhinitis had greater HRQL impairment, as measured by the Rhinasthma, than subjects with either asthma or rhinitis alone. The Rhinasthma correlated significantly (P < .05) with the SF-12, EQ-5D, and Marks Asthma Quality-of-Life in the anticipated direction consistent with the underlying constructs. In multiple logistic regression, poorer Rhinasthma HRQL was associated with significantly (P < .05) increased odds of both asthma- and rhinitis-related disability even after taking into account physical health status as measured by the SF-12.

CONCLUSION

The 28-item English adaptation of Rhinasthma performs well in assessing HRQL in patients with asthma, rhinitis, or both conditions combined.

Studies systematically comparing the performance of health-related quality-of-life (HRQoL) instruments in pulmonary arterial hypertension (PAH) are lacking. We sought to address this by comparing cardiac and respiratory-specific measures of HRQoL in PAH. We prospectively assessed HRQoL in 128 patients with catheterisation-confirmed PAH at baseline and at 6, 12 and post-24 month follow-up visits. Cardiac-specific HRQoL was assessed using the Minnesota Living with Heart Failure Questionnaire (LHFQ); respiratory-specific HRQoL was assessed using the Airways Questionnaire 20 (AQ20); and general health status was assessed using the 36-item Short Form physical component summary (SF-36 PCS). The LHFQ and AQ20 were highly intercorrelated. Both demonstrated strong internal consistency and converged with the SF-36 PCS. Both discriminated patients based on World Health Organization (WHO) functional class, 6-min walking distance (6MWD) and Borg dyspnoea index (BDI), with the exception of a potential floor effect associated with low 6MWD. The LHFQ was more responsive than the AQ20 to changes over time in WHO functional class, 6MWD and BDI. In multivariate analyses, the LHFQ and AQ20 were each longitudinal predictors of general health status, independent of functional class, 6MWD and BDI. In conclusion, both cardiac-specific and respiratory-specific measures appropriately assess HRQoL in most patients with PAH. Overall, the LHFQ demonstrates stronger performance characteristics than the AQ20.

A recurrent clinical dilemma in the management of patients with painful metastatic lesions is achieving a balance between effective analgesic therapies versus intolerable side effects, in particular altered mental status. We present the case of an immunosuppressed patient post-lung transplant who was suffering from intractable pain caused by widely metastatic squamous cell carcinoma. The patient's progressive, excruciating neuropathic pain was localized to the area of the left wrist and forearm. Additionally, the patient complained of moderate pain at sites of tumor involvement on her right arm and scalp. Attempts to adequately manage her left upper extremity pain included a combination of pharmacologic treatments intended to treat neuropathic pain (gabapentin, SNRI, ketamine, opioids) and focused regional analgesia (infraclavicular infusion of local anesthetic). However, the patient developed intolerable side effects including altered mental status and delirium associated with the systemic agents and suboptimal control with the infraclavicular infusion. Given that the most severe pain was well localized, we undertook a diagnostic block of the cutaneous nerves of the left forearm. As this intervention significantly reduced her pain, we subsequently performed neurectomies to the left superficial radial nerve, lateral cutaneous nerve of the forearm and the posterior cutaneous nerve of the forearm. This resulted in immediate and continued relief of her left upper extremity pain without an altered mental status. Residual focal pain from lesions over her right arm and scalp was successfully managed with daily topical applications of lidocaine and capsaicin cream. Successful pain control continued until the patient's death five months later.

PURPOSE

We sought to quantify the impact of respiratory muscle and lower extremity strength on exercise capacity and lower extremity function (LEF) in patients with chronic obstructive pulmonary disease (COPD).

METHODS

In 828 persons with COPD, we assessed the impact of reduced respiratory (maximum inspiratory pressure, MIP) and lower extremity muscle strength (quadriceps strength, QS) on exercise capacity (6-minute walk test, 6MWT), and LEF (short physical performance battery). Multiple regression analyses taking into account key covariates, including lung function and smoking, tested the associations between muscle strength and exercise and functional capacity.

RESULTS

For each 0.5 SD decrement in QS, men walked 18.3 m less during 6MWT (95% confidence interval [CI], -24.1 to -12.4); women 25.1 m less (95% CI, -31.1 to -12.4). For each 0.5 SD decrement in MIP, men walked 9.4 m less during 6MWT (95% CI, -15.2 to -3.6); women 8.7 m less (95% CI, -14.1 to -3.4). For each 0.5 SD decrease in QS, men had a 1.32 higher odds (95% CI, 1.11-1.15) of poor LEF; women had a 1.87 higher odds (95% CI, 1.54-2.27). Lower MIP (per 0.5 SD) was associated with increased odds of poor LEF in women (odds ratio = 1.18; 95% CI, 1.00-1.39), but not in men (odds ratio = 1.10; 95% CI, 0.93-1.31).

CONCLUSIONS

In COPD, reduced respiratory and lower extremity muscle strength are associated with decreased exercise and functional capacity. Muscle weakness is likely an important component of impairment and disability in patients with COPD.

BACKGROUND

Matrix metalloproteinase-9 (MMP-9) may be important in the progression of emphysema, but there have been few longitudinal clinical studies of MMP-9 including pulmonary status and COPD exacerbation outcomes.

METHODS

We utilized data from the placebo arm (n=126) of a clinical trial of patients with alpha1-antitrypsin deficiency (AATD) and emphysema to examine the links between plasma MMP-9 levels, pulmonary status, and COPD exacerbations over a one year observation period. Pulmonary function, computed tomography lung density, incremental shuttle walk test (ISWT), and COPD exacerbations were assessed at regular intervals over 12 months. Prospective analyses used generalized estimating equations to incorporate repeated longitudinal measurements of MMP-9 and all endpoints, controlling for age, gender, race-ethnicity, leukocyte count, and tobacco history. A secondary analysis also incorporated highly-sensitive C-reactive protein levels in predictive models.

RESULTS

At baseline, higher plasma MMP-9 levels were cross-sectionally associated with lower FEV1 (p=0.03), FVC (p<0.001), carbon monoxide transfer factor (p=0.03), resting oxygen saturation (p=0.02), and ISWT distance walked (p=0.02) but were not associated with radiographic lung density or total lung capacity (TLC). In longitudinal analyses, MMP-9 predicted a further decline in transfer factor (p=0.04) and oxygen saturation (p<0.001). MMP-9 also predicted worsening lung density (p=0.003), increasing TLC (p=0.02), and more frequent COPD exacerbations over follow-up (p=0.003). Controlling additionally for hs-CRP levels did not substantively change the longitudinal associations between MMP-9 and these outcomes.

CONCLUSIONS

Increased plasma MMP-9 levels generally predicted pulmonary status declines, including worsening transfer factor and lung density as well as greater COPD exacerbations in AATD-associated emphysema.

INTRODUCTION

People with α1-antitrypsin deficiency are at increased risk for the development of chronic obstructive pulmonary disease. Previous retrospective epidemiologic studies have found that exposure to occupational dust among those with α1-antitrypsin deficiency is a risk factor at the group level for poorer lung function, but on an individual clinical basis, a causal attribution can be difficult to establish.

CASE PRESENTATION

We describe the case of a 68-year-old Caucasian man with a 25 pack-year smoking history who presented with new-onset dyspnea on exertion in the setting of workplace dust exposure. During his evaluation, he was found to have α1-antitrypsin deficiency with evidence of development of pulmonary emphysema. Workplace spirometric monitoring over 10 years of surveillance for an on-the-job respirator fit program demonstrated a sharp downward slope in forced expiratory volume in one second, or FEV1, during his periods of most significant dust exposure, which was attenuated after discontinuation of his workplace exposure.

CONCLUSION

Patients with α1-antitrypsin disease should be assessed for occupational exposures and closely monitored for work-accelerated progression of lung function decline. More generally, this case report supports the biological plausibility of occupationally associated chronic obstructive pulmonary disease, underscoring that work-associated pulmonary disease can be multi-factorial.