RESEARCH ARTICLE
How does ageing affect the impact of medically unexplained symptoms and medically explained symptoms on healthrelated quality of life? Peter H. Hilderink1, Rose Collard2, Judith G. M. Rosmalen3 and Richard C. Oude Voshaar3 1
SeniorBeter, Practice for Old Age Psychiatry, Gendt, Netherlands Radboud University Nijmegen Medical Centre, Department of Psychiatry, Nijmegen Centre for Evidence-Based Practice, Nijmegen, Netherlands 3 University of Groningen, University Medical Center Groningen, Groningen, Netherlands Correspondence to: P. H. Hilderink, SeniorBeter, E-mail: [email protected] 2
Background: Physical symptoms significantly impair health-related quality of life (HRQoL), but age effects and differential effects of medically unexplained symptoms (MUS) and medically explained symptoms (MES) have hardly been examined. Our objective was to determine the effect of age on the impact of MUS and MES on HRQoL. Methods: In a population-based cohort (n = 946, aged 28–75 years), MUS and MES were measured using the Composite International Diagnostic Interview and HRQoL using the EuroQol-5 dimensions (EQ-5D). Using multiple linear regression, we regressed MUS, MES and their interaction with age on HRQoL, adjusted for socio-demographic variables and the presence of depressive and anxiety disorders. In case of significant interaction terms, age-stratified results will be presented. Results: In the whole study population, the association between MUS and HRQoL was stronger (β = 0.35; p < 0.001) than between MES and HRQoL (β = 0.26; p < 0.001). Adjusted for depressive and anxiety disorders, differences between these associations decline (MUS: β = 0.28, p < 0.001; MES: β = 0.25, p < 0.001). Age significantly interacted with number of MUS in explaining variance in HRQoL but not with the number of MES. The impact of MUS on HRQoL is much larger in people aged below 65 years (β = 0.39, p < 0.001) versus those aged 65 years and over (β = 0.21, p = 0.002). In the older group, the association between MUS and HRQoL lost significance when adjusted for depressive and anxiety disorders (β = 0.12 p = 0.062). Conclusion: Our results show that age affects the association between MUS and HRQoL, which suggest that older persons cope better with MUS than younger persons. Copyright # 2014 John Wiley & Sons, Ltd. Key words: medically unexplained symptoms; quality of life; aged; medically explained; symptoms History: Received 25 May 2014; Accepted 5 September 2014; Published online in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/gps.4219
Introduction Physical symptoms account for the majority of consultation in primary care, and at least a third of these symptoms remain medically unexplained (Kroenke, 2003). The measurement of MUS is time consuming and might even be unreliable (Creed et al., 2010). It has been postulated that the total number of physical Copyright # 2014 John Wiley & Sons, Ltd.
symptoms, both medically explained and unexplained symptoms, is most informative in estimating healthrelated quality of life (HRQoL) (olde Hartman et al., 2004; Tomenson et al., 2013). Two cross-sectional and one prospective cohort study indeed found a significant correlation between a high somatic symptom count, including both medically explained and unexplained symptoms, and impaired health status
Int J Geriatr Psychiatry 2014
P. H. Hilderink et al.
(Kroenke, 2003; Barsky et al., 2005; Creed et al., 2012). Whether medically unexplained symptoms (MUSs) cause the same degree of morbidity and reduction in HRQoL as medically explained symptoms (MESs) across the lifespan, however, is not clear. Studies in adult populations have shown that compared with MES, MUS are associated with a similar (Klaus et al., 2012) or even greater level of disability (Feder et al., 2001; Koch et al., 2007). In a primary care population with a mean age around 40 years, patients with MUS had significantly more physical symptoms, higher levels of anxiety and depression, and a lower HRQoL compared with patients with MES (Duddu et al., 2008). In this study, occupational status, level of education, anxiety, depression, and the number of physical symptoms independently predicted HRQoL, whereas a distinction between medically explained or unexplained symptoms did not (Duddu et al., 2008). A higher prevalence of affective disorders as well as higher number of somatic symptoms may thus explain the differential impact of MES and MUS on HRQoL. Because MES increase with ageing, one would expect lower HRQoL in older persons. Nonetheless, two thirds of hospitalised older patients report good HRQoL, which suggest minimal impact of MES on HRQoL in later life (Helvik et al., 2010). Empirical data about MUS in later life are scarce (Wijeratne et al., 2003). A recent review suggests that prevalence rates of MUS are stable until the age of 65 years and decrease thereafter (Hilderink et al., 2012). The impact of MUS on the HRQoL in old age has not been reported yet. The primary aim of the present study is to examine the effect of age on the impact of MUS and MES on HRQoL. We hypothesise that (1) MUS are more strongly associated with impaired HRQoL than MES, (2) the differential impact of MUS and MES on HRQoL can be explained by comorbid depressive and anxiety disorders in patients with MUS as compared with patients with MES, and (3) the impact of MES on HRQoL decreases with age.
study population for this substudy has previously been reported in detail (Kingma et al., 2012). In summary, all inhabitants of the city of Groningen between the ages of 28 and 75 years (85 421 subjects) received an invitation by post to send in a morning urine sample and to fill out a short questionnaire. A total of 40 856 subjects (47.8%) responded. After exclusion of subjects with insulin-dependent diabetes mellitus and pregnant women, all subjects with a urinary albumin concentration of >10 mg/l (n = 7768), together with a randomly selected control group with a urinary albumin concentration of
How does ageing affect the impact of medically unexplained symptoms and medically explained symptoms on healthrelated quality of life? Peter H. Hilderink1, Rose Collard2, Judith G. M. Rosmalen3 and Richard C. Oude Voshaar3 1
SeniorBeter, Practice for Old Age Psychiatry, Gendt, Netherlands Radboud University Nijmegen Medical Centre, Department of Psychiatry, Nijmegen Centre for Evidence-Based Practice, Nijmegen, Netherlands 3 University of Groningen, University Medical Center Groningen, Groningen, Netherlands Correspondence to: P. H. Hilderink, SeniorBeter, E-mail: [email protected] 2
Background: Physical symptoms significantly impair health-related quality of life (HRQoL), but age effects and differential effects of medically unexplained symptoms (MUS) and medically explained symptoms (MES) have hardly been examined. Our objective was to determine the effect of age on the impact of MUS and MES on HRQoL. Methods: In a population-based cohort (n = 946, aged 28–75 years), MUS and MES were measured using the Composite International Diagnostic Interview and HRQoL using the EuroQol-5 dimensions (EQ-5D). Using multiple linear regression, we regressed MUS, MES and their interaction with age on HRQoL, adjusted for socio-demographic variables and the presence of depressive and anxiety disorders. In case of significant interaction terms, age-stratified results will be presented. Results: In the whole study population, the association between MUS and HRQoL was stronger (β = 0.35; p < 0.001) than between MES and HRQoL (β = 0.26; p < 0.001). Adjusted for depressive and anxiety disorders, differences between these associations decline (MUS: β = 0.28, p < 0.001; MES: β = 0.25, p < 0.001). Age significantly interacted with number of MUS in explaining variance in HRQoL but not with the number of MES. The impact of MUS on HRQoL is much larger in people aged below 65 years (β = 0.39, p < 0.001) versus those aged 65 years and over (β = 0.21, p = 0.002). In the older group, the association between MUS and HRQoL lost significance when adjusted for depressive and anxiety disorders (β = 0.12 p = 0.062). Conclusion: Our results show that age affects the association between MUS and HRQoL, which suggest that older persons cope better with MUS than younger persons. Copyright # 2014 John Wiley & Sons, Ltd. Key words: medically unexplained symptoms; quality of life; aged; medically explained; symptoms History: Received 25 May 2014; Accepted 5 September 2014; Published online in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/gps.4219
Introduction Physical symptoms account for the majority of consultation in primary care, and at least a third of these symptoms remain medically unexplained (Kroenke, 2003). The measurement of MUS is time consuming and might even be unreliable (Creed et al., 2010). It has been postulated that the total number of physical Copyright # 2014 John Wiley & Sons, Ltd.
symptoms, both medically explained and unexplained symptoms, is most informative in estimating healthrelated quality of life (HRQoL) (olde Hartman et al., 2004; Tomenson et al., 2013). Two cross-sectional and one prospective cohort study indeed found a significant correlation between a high somatic symptom count, including both medically explained and unexplained symptoms, and impaired health status
Int J Geriatr Psychiatry 2014
P. H. Hilderink et al.
(Kroenke, 2003; Barsky et al., 2005; Creed et al., 2012). Whether medically unexplained symptoms (MUSs) cause the same degree of morbidity and reduction in HRQoL as medically explained symptoms (MESs) across the lifespan, however, is not clear. Studies in adult populations have shown that compared with MES, MUS are associated with a similar (Klaus et al., 2012) or even greater level of disability (Feder et al., 2001; Koch et al., 2007). In a primary care population with a mean age around 40 years, patients with MUS had significantly more physical symptoms, higher levels of anxiety and depression, and a lower HRQoL compared with patients with MES (Duddu et al., 2008). In this study, occupational status, level of education, anxiety, depression, and the number of physical symptoms independently predicted HRQoL, whereas a distinction between medically explained or unexplained symptoms did not (Duddu et al., 2008). A higher prevalence of affective disorders as well as higher number of somatic symptoms may thus explain the differential impact of MES and MUS on HRQoL. Because MES increase with ageing, one would expect lower HRQoL in older persons. Nonetheless, two thirds of hospitalised older patients report good HRQoL, which suggest minimal impact of MES on HRQoL in later life (Helvik et al., 2010). Empirical data about MUS in later life are scarce (Wijeratne et al., 2003). A recent review suggests that prevalence rates of MUS are stable until the age of 65 years and decrease thereafter (Hilderink et al., 2012). The impact of MUS on the HRQoL in old age has not been reported yet. The primary aim of the present study is to examine the effect of age on the impact of MUS and MES on HRQoL. We hypothesise that (1) MUS are more strongly associated with impaired HRQoL than MES, (2) the differential impact of MUS and MES on HRQoL can be explained by comorbid depressive and anxiety disorders in patients with MUS as compared with patients with MES, and (3) the impact of MES on HRQoL decreases with age.
study population for this substudy has previously been reported in detail (Kingma et al., 2012). In summary, all inhabitants of the city of Groningen between the ages of 28 and 75 years (85 421 subjects) received an invitation by post to send in a morning urine sample and to fill out a short questionnaire. A total of 40 856 subjects (47.8%) responded. After exclusion of subjects with insulin-dependent diabetes mellitus and pregnant women, all subjects with a urinary albumin concentration of >10 mg/l (n = 7768), together with a randomly selected control group with a urinary albumin concentration of
