The incremental burden of pain in patients with depression: results of a Japanese survey

Vietri et al. BMC Psychiatry (2015) 15:104 DOI 10.1186/s12888-015-0488-8 RESEARCH ARTICLE Open Access The incremental burden of pain in patients with depression: results of a Japanese survey Jeffrey Vietri1*, Tempei Otsubo2, William Montgomery3, Toshinaga Tsuji4 and Eiji Harada5 Abstract Background: Major depressive disorder (MDD) is a chronic mental illness which affects an estimated 3% of the Japanese population. Many patients with MDD report painful physical symptoms, and research outside of Japan suggests such patients may represent a subtype of depression which is more severe and difficult to treat. There is no evidence available about the characteristics or incremental burden of these patients in Japan. The objective of this study was to quantify the incremental burden of physical pain among individuals in Japan diagnosed with depression. Methods: Data for individuals age 18 and older who reported a physician diagnosis of depression were obtained from the Japan National Health and Wellness Survey (NHWS). Respondents who also reported physical pain were matched to respondents who did not report pain using propensity scores and compared using bivariate statistics. Measures included Patient Health Questionnaire (PHQ-9) for depression severity, Medical Outcomes Study 12-Item Short Form Survey Instrument (SF-12v2) for health-related quality of life, the Work Productivity and Activity Impairment (WPAI) for work and activity impairment, and 6-month report of health care use. Results: Individuals with depression who reported physical pain had higher PHQ-9 depression scores (14.3 vs. 11.1, p<0.001), lower health-related quality of life (Mental Component Summary score [MCS] 29.1 vs. 32.0, p<0.01; Physical Component Summary score [PCS] 43.0 vs. 47.2, p<0.001; health utility [SF-6D] 0.567 vs. 0.613, p<0.001), more presenteeism (46.3% vs. 36.8%, p<0.01), more overall work impairment (51.4% vs. 42.3%, p<0.01), more activity impairment (55.4% vs. 43.9%, p<0.001), and reported using more health care provider visits in the prior 6 months (17.7 vs. 12.8, p<0.01) as well as hospitalizations (1.7 vs. 0.8, p<0.05) relative to propensity-score matched controls without pain. Absenteeism (13.1% vs. 11.4%, p=0.51) and emergency room visits (0.31 vs. 0.35, p=0.76) were not significantly different between the two matched groups. Conclusions: Individuals whose depression is accompanied by physical pain have a higher burden of illness than those whose depression does not include physical pain. Clinicians should take the presence of pain into account and consider treating both the physical and emotional symptoms of these patients. Keywords: Depression, Pain, Painful physical symptoms, Quality of life, Work productivity, Health care use Background Major Depressive Disorder (MDD) is a severe recurring illness associated with depressed mood, loss of interest or pleasure, feelings of guilt or low self-worth, disturbed sleep or appetite, psychomotor agitation or slowing, low energy, poor concentration, and risk of suicide. Depression has a considerable impact on both patients with the condition as well as on broader society [1-3]. MDD is one * Correspondence: 1 Kantar Health, Health Outcomes Practice, Via Paleocapa 7, 20121 Milan, Italy Full list of author information is available at the end of the article of the most common mood disorders, with a 12-month prevalence of approximately 3% in Japan according to the World Health Organization Composite International Diagnostic Interview [4]. While the prevalence of mood disorders such as MDD is considerably lower in Japan than in many Western countries, there are significant cohort differences in susceptibility to mood disorders, with higher prevalence in younger generations [5]. The higher lifetime prevalence expected for these younger people suggests an increase in the societal burden of depression is likely in the future. Patients suffering from © 2015 Vietri et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Vietri et al. BMC Psychiatry (2015) 15:104 depression sometimes present with painful physical symptoms as well [6], which many exacerbate this burden. As is the case with depression, chronic pain conditions have been found to lead to substantial disability [7-10]. Furthermore, previous research has shown that a high proportion of patients with depression experience a range of painful physical symptoms [11,12]. The subset of depressed patients who experience such pain symptoms appears to have a particularly high level of disability. Relative to depressed patients without comorbid pain, individuals with depression and pain have greater limitations in daily activities [11,12], have worse health related quality of life (HRQoL) [11-15], and are more likely to be unemployed due to disability [11,16]. Patients with both depression and pain also use more inpatient and outpatient health care resources and are more expensive to treat [11,14,17-20]. In fact, it has been suggested that patients with depression and painful physical symptoms may constitute a distinct subpopulation of patients which is more difficult to treat [21]. The connection between painful physical symptoms and greater depression severity, lower quality of life, and greater health care use was recently demonstrated in a multi-country prospective study of individuals presenting with an acute depressive episode in East Asia [22]. In that study, painful physical symptoms were reported by approximately half of the patients enrolled, and such symptoms were associated with clinically important decrements in quality of life at 3 months post-baseline [22]. This decrement was maintained after adjusting for covariates including baseline level of depression [23]. Similarly, worse pain symptoms were associated with lower remission rates of depression [24]. However, Japan was not included in the aforementioned prospective study, and little real-world data from Japan has been reported regarding either the incremental burden of physical pain on patients with depression or the burden on the Japanese health care system. Research describing patient-reported health outcomes such as HRQoL and impairment to work and daily activities among these individuals is particularly scarce. Therefore the objective of this study was to assess the incremental burden of physical pain in real-world patients with depression in Japan, including the association between the presence of physical pain and the severity of depression symptoms. Methods Data source Data were provided by (...truncated)