PurposeTo examine the efficacy and safety of duloxetine in Japanese patients with knee pain due to osteoarthritis.Patients and methodsPatients were randomized to receive duloxetine 60 mg/day or placebo for 14 weeks in a double-blind manner (ClinicalTrials.gov Identifier: NCT02248480). The primary efficacy endpoint was mean change in Brief Pain Inventory pain severity (BPI-Severity) average pain. Secondary endpoints included improvement in other BPI-Severity scales, Patient Global Impression of Improvement, Clinical Global Impressions of Severity, health-related quality of life (HRQoL) scales, range of motion of the knee joint, safety and tolerability, and structural changes on X-ray images.ResultsOf the 354 randomized patients, 161 in the duloxetine group and 162 in the placebo group completed the study. BPI-Severity average pain improved significantly with duloxetine vs. placebo (−2.57 vs. −1.80; adjusted mean difference: −0.77; 95% CI: −1.11 to −0.43; P<0.0001). Secondary efficacy endpoints and most HRQoL scales showed greater improvements in the duloxetine group than the placebo group. Adverse events observed in ≥5% of patients that were more frequent in the duloxetine than placebo group were somnolence, constipation, dry mouth, nausea, malaise, and decreased appetite. There were no marked changes in range of motion of the knee joint (efficacy), X-ray images, or Kellgren–Lawrence grade (safety) in either group.ConclusionDuloxetine reduced pain and improved function in patients with knee osteoarthritis, without causing X-ray abnormalities or altered knee joint mobility. Reduced pain was associated with improved HRQoL. Adverse events were consistent with duloxetine’s known safety profile.

BackgroundChronic low back pain (CLBP) is associated with significant disability and reductions in health related quality of life (HRQoL), which can negatively impact overall function and productivity. Depression is also associated with painful physical symptoms, and is often present in patients with chronic pain. However, the incremental burden associated with depression or symptoms of depression among CLBP patients is not well understood. The objective of this study was to investigate the impact of depression on HRQoL in CLBP and to assess the relationship between depression and work impairment and healthcare use among CLBP patients in Japan.MethodsData were extracted from the 2014 Japan National Health and Wellness Survey (N = 30,000). CLBP was defined by report of diagnosed low back pain ≥3 months duration. Depression was assessed using the Patient Health Questionnaire (PHQ-9). Measurements assessed included pain, HRQoL, labor force participation, work productivity and healthcare utilization. Patients with depression (PHQ-9 ≥ 10) were compared to patients without depression (PHQ-9 < 10) using t-tests for continuous and count variables and chi-square for categorical variables, which were followed by generalized linear models adjusted for covariates. The association between presenteeism and other patient outcomes and characteristics was analysed using nonparametric correlations (Spearman’s rho).ResultsDepressed CLBP patients had significantly more severe pain and higher levels of pain compared with patients without depression (P < 0.001). Depression was associated with worse HRQoL in CLBP patients. Presenteeism, overall work impairment and activity impairment were 1.8, 1.9 and 1.7 times as high, respectively, among those with depression relative to those without depression. CLBP patients with depression had almost twice as many healthcare provider visits in 6 months than those without depression. The pattern of results remained consistent after adjustment for sociodemographic and general health characteristics. Analysis also indicated presenteeism was closely related to overall work impairment (rho = 0.99).ConclusionsDepression among CLBP patients in Japan was associated with higher pain scores and lower HRQoL scores, as well as lower labor productivity and increased healthcare use. Screening for depression in CLBP patients should be an essential part of CLBP patient care.

BackgroundOsteoarthritis (OA) is one of the most common causes of health and work impairment; however, this relationship, especially in Japan, is not well characterized. This study examined work impairment and OA in Japanese workers, specifically the relationship with health-related quality of life (HRQoL) and health status.MethodsThis retrospective, cross-sectional observational study included the data of employed adults with a self-reported OA diagnosis from the 2014 Japan National Health and Wellness Survey. Presenteeism and absenteeism were classified using the Work Productivity and Activity Impairment (WPAI) questionnaire for impairment at work in the past week. Outcome variables included health-related quality of life, which was measured with the revised Medical Outcomes Study 36-Item Short Form Survey Instrument Health Survey (SF-36v2), and depression symptom severity, which was assessed using the Patient Health Questionnaire-9 (PHQ-9).ResultsThe majority (71.2%) of respondents with OA reported presenteeism, and 11.1% reported absenteeism. Presenteeism and absenteeism were both associated with younger age; a lower proportion of respondents with than without presenteeism were married or living with a partner, and a greater proportion of those with absenteeism had comorbid conditions (for all, p < 0.05). Respondents with than without presenteeism reported greater use of medications to relieve OA symptoms (37.3% versus 20.9%, p < 0.05), and those with than without absenteeism reported more frequent arthritis-related problems (p = 0.032). Among those with presenteeism, depression severity was higher (5.8 ± 6.0) than for those with no presenteeism (2.9 ± 4.3; p < 0.001). Presenteeism was associated with impairments in HRQoL on all metrics for patients with OA, with lower mental (6.4 points) and physical (4.8 points) component scores on the SF-36v2 (for all, p < 0.001).ConclusionsSeven out of every 10 patients with OA experienced presenteeism, whereas one out of 10 reported absenteeism. OA respondents with presenteeism also showed greater medication use, lower HRQoL across both mental and physical components, and higher depression severity. Workplace interventions and effective treatment options are necessary strategies for improving the health of workers with OA in Japan.

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ObjectivesThis study investigated the relationship between presenteeism and health-related quality of life (HRQoL) among Japanese adults with chronic lower back pain (CLBP).DesignThis was a retrospective, cross-sectional study.SettingData were collected via a self-administered online survey of the Japanese adult general population.ParticipantsThe present study used 2014 Japan National Health and Wellness Survey (NHWS) data (n=30 000). Specifically, data were included from NHWS respondents who self-reported being employed in the past week and having experienced LBP in the past month, with these symptoms lasting for at least 3 months (n=239). 84 (35.1%) participants in this study were female.Primary and secondary outcome measuresPresenteeism and HRQoL were measured using the Work Productivity and Activity Impairment Questionnaire-General Health (categorical (none: 0%, low: 10%–20%, high: ≥30%) and continuous) and Medical Outcomes Study 36-Item Short Form Health Survey, respectively. Covariates included patient demographics, health characteristics, pain characteristics and depression severity (Patient Health Questionnaire).ResultsPresenteeism was reported by 77.4% of respondents. High (vs no) presenteeism related to more severe pain in the prior week (4.9±2.2 vs 3.6±2.1, p=0.001) and currently (5.1±2.1 vs 3.9±3.9, p=0.007), more pain sites (1.9±1.6 vs 1.1±1.4, p=0.004) and greater depression severity (7.5±6.5 vs 3.6±3.6, p<0.001). Adjusting for covariates, high (vs no) presenteeism related to lower mental and physical HRQoL. For low versus no presenteeism, significant HRQoL differences were observed in general health (43.0, 95% CI 40.3 to 45.6 vs 46.9, 95% CI 43.9 to 49.8, p=0.015).ConclusionsMost respondents experienced presenteeism. Those with high or low presenteeism had poorer HRQoL than respondents with no presenteeism. Monitoring presenteeism rates may help identify workers with an unmet need for better CLBP-related pain management.