569795 research-article2015
ANP0010.1177/0004867415569795Australian & New Zealand Journal of PsychiatryCampbell et al.
Research Australian & New Zealand Journal of Psychiatry 1–9 DOI: 10.1177/0004867415569795
The prevalence and correlates of chronic pain and suicidality in a nationally representative sample
© The Royal Australian and New Zealand College of Psychiatrists 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav anp.sagepub.com
Gabrielle Campbell1, Shane Darke1, Raimondo Bruno2 and Louisa Degenhardt1
Abstract Background: Research suggests that people suffering from chronic pain have elevated rates of suicidality. With an ageing population, more research is essential to gain a better understanding of this association. Aims: To document the prevalence and correlates of chronic pain and suicide, and estimate the contribution of chronic pain to suicidality. Method: Data from the 2007 Australian National Survey of Mental Health and Wellbeing, a nationally representative household survey on 8841 people, aged 16–85 years, was analysed. Results: The odds of lifetime and past 12-month suicidality were two to three times greater in people with chronic pain. Sixty-five percent of people who attempted suicide in the past 12 months had a history of chronic pain. Chronic pain was independently associated with lifetime suicidality after controlling for demographic, mental health and substance use disorders. Conclusions: Health care professionals need to be aware of the risk of suicidality in patients with chronic pain, even in the absence of mental health problems. Keywords Chronic non-cancer pain, prevalence, suicide
Introduction Chronic pain, defined as pain that persists for greater than three months (Merskey and Bogduk, 1994), is a common worldwide complaint, with rates in the general population estimated from 17% (Blyth et al., 2001) to 41% (Tsang et al., 2008). Chronic pain is associated with poorer physical health (Eriksen et al., 2006), poorer quality of life (Hagg et al., 2003; Ojala et al., 2014) and a greater risk of developing depression (Currie and Wang, 2004) and other mental health problems (Dersh et al., 2002; McWilliams et al., 2003). Although there are behavioural, physical and medication interventions for chronic pain, it is often the case that many patients have to accept a lifetime treatment plan for the management of their pain, which may not alleviate the pain completely (Breivik et al., 2006). It is not unexpected then, that rates of suicidality (defined as ideation, plans and attempts) are elevated amongst this group (Meilman, 1984). Emerging research suggests that people suffering from chronic pain have almost double the
risk of death by suicide (Tang and Crane, 2006). Amongst people with chronic pain, rates of lifetime ideation range from 21% to 50%, current ideation from 0% to 24%, and rates of lifetime suicidal attempts from 5% to 14% (Tang and Crane, 2006). These studies, however, have generally been based on small, clinical samples, so it is unknown if the same pattern exists in the general pain population. Further, recent epidemiological research suggests chronic pain is independently associated with suicidality after controlling for demographic and mental health factors (Braden and Sullivan, 2008; Ilgen et al., 2013; Ratcliffe et al., 2008). 1National 2School
Drug and Alcohol Research Centre, UNSW, Sydney, Australia of Medicine, University of Tasmania, Hobart, Australia
Corresponding author: Gabrielle Campbell, National Drug and Alcohol Research Centre, UNSW, Sydney, NSW 2052, Australia. Email: [email protected]
Australian & New Zealand Journal of Psychiatry Downloaded from anp.sagepub.com at UNIV NEBRASKA LIBRARIES on March 16, 2015
2
ANZJP Articles
With an ageing population, and the likely increase in chronic pain, the issue of chronic pain and its relationship to suicidality is of timely importance. To our knowledge, there has been no study that has estimated the contribution that chronic pain may make to suicidality in the general population, and there are few existing data on the relationship between chronic pain and suicide in the Australian population. The aims of the current study were to: •• document the prevalence of chronic pain in Australia; •• examine lifetime and past 12-month suicidal behaviours in people with chronic pain, and estimate the contribution that a history of chronic pain may make to suicidality in the general population; •• determine whether chronic pain is associated with suicide when controlling for socio-demographic variables and mental health diagnoses; •• determine the risk factors for the past 12-month suicidal behaviours amongst people with chronic pain.
Method Sample Data from the Confidentialised Unit Record File (CURF) for the Australian 2007 National Survey of Mental Health and Wellbeing (NSMHWB) (Slade, et al., 2009) were obtained from the Australian Bureau of Statistics (ABS). The 2007 NSMHWB was conducted by trained interviewers from the ABS between August and December of 2007. The aim of the survey was to provide representative estimates on a national level. The 2007 NSMHWB sample was based on a stratified, multistage area probability sample of people aged 16–85 years in rural and urban private dwellings across all Australian States and Territories. The area-based selection ensured that all sections of the population living in private dwelling within the geographical scope of the survey were represented, representing a total of 17,352 dwellings. Special dwellings (hospitals, nursing homes, gaols, hotels) and dwellings in remote and sparsely settled regions of the country were not sampled, which reduced the effective sample size to 14,805 dwellings. All interviews were conducted in English, meaning that non-English speakers were excluded from the sample. Each interview was conducted in person and took approximately 90 minutes to complete. There were 8841 fully responding participants, which represented a rate of 60%. Owing to the lower than expected response rate (it was expected that a 75% response rate would be achieved), extensive non-response analyses were undertaken to assess the reliability of the survey estimates. A purposive sample of fully non-responding households in two metropolitan areas, Sydney and Perth, was followed up with a short-form interview, to gain a qualitative assessment of non-response bias. The study indicated the impact of non-response to be small at the aggregate level, but possible underestimation of the prevalence of mental disorders
may exist for men, young persons and the Perth population. The final sample represented an estimated population count (EPC) of 16,015,000 Australian adults. For further information about the procedure and instrument see Slade et al., (2009).
Survey The 2007 NSMHWB was based on the World Mental Health Survey Initiative version of the Composite International Diagnostic Interview (WMH-CIDI) (Kessler and Ustun, 2004). This interview has undergone extensive methodological development and testing and has been used in household surveys in at least 28 countries around the world. This version of the instrument collects both diagnostic information on a broad range of mental disorders and information on risk factors, impacts, patterns and treatment of mental disorders. There were some modifications made to the WMH-CIDI to tailor the survey to the Australian context. The following questions and measures from the 2007 NSMHWB were used in the current study. Chronic pain. The chronic conditions section was based on the WMH-CIDI chronic conditions module. The information provided is self-reported by the respondent and is not verified by a medical practitioner. The current study used questions that related to the presence of arthritis, migraines and back/neck pain that had persisted for a period of 6 months. A combined category of ‘any pain’ was created on the basis of endorsement of any one chronic pain condition (arthritis/migraines, back/neck problems). Socio-demographics. Consistent with Ratcliffe et al., (2008), age was split into categories of
ANP0010.1177/0004867415569795Australian & New Zealand Journal of PsychiatryCampbell et al.
Research Australian & New Zealand Journal of Psychiatry 1–9 DOI: 10.1177/0004867415569795
The prevalence and correlates of chronic pain and suicidality in a nationally representative sample
© The Royal Australian and New Zealand College of Psychiatrists 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav anp.sagepub.com
Gabrielle Campbell1, Shane Darke1, Raimondo Bruno2 and Louisa Degenhardt1
Abstract Background: Research suggests that people suffering from chronic pain have elevated rates of suicidality. With an ageing population, more research is essential to gain a better understanding of this association. Aims: To document the prevalence and correlates of chronic pain and suicide, and estimate the contribution of chronic pain to suicidality. Method: Data from the 2007 Australian National Survey of Mental Health and Wellbeing, a nationally representative household survey on 8841 people, aged 16–85 years, was analysed. Results: The odds of lifetime and past 12-month suicidality were two to three times greater in people with chronic pain. Sixty-five percent of people who attempted suicide in the past 12 months had a history of chronic pain. Chronic pain was independently associated with lifetime suicidality after controlling for demographic, mental health and substance use disorders. Conclusions: Health care professionals need to be aware of the risk of suicidality in patients with chronic pain, even in the absence of mental health problems. Keywords Chronic non-cancer pain, prevalence, suicide
Introduction Chronic pain, defined as pain that persists for greater than three months (Merskey and Bogduk, 1994), is a common worldwide complaint, with rates in the general population estimated from 17% (Blyth et al., 2001) to 41% (Tsang et al., 2008). Chronic pain is associated with poorer physical health (Eriksen et al., 2006), poorer quality of life (Hagg et al., 2003; Ojala et al., 2014) and a greater risk of developing depression (Currie and Wang, 2004) and other mental health problems (Dersh et al., 2002; McWilliams et al., 2003). Although there are behavioural, physical and medication interventions for chronic pain, it is often the case that many patients have to accept a lifetime treatment plan for the management of their pain, which may not alleviate the pain completely (Breivik et al., 2006). It is not unexpected then, that rates of suicidality (defined as ideation, plans and attempts) are elevated amongst this group (Meilman, 1984). Emerging research suggests that people suffering from chronic pain have almost double the
risk of death by suicide (Tang and Crane, 2006). Amongst people with chronic pain, rates of lifetime ideation range from 21% to 50%, current ideation from 0% to 24%, and rates of lifetime suicidal attempts from 5% to 14% (Tang and Crane, 2006). These studies, however, have generally been based on small, clinical samples, so it is unknown if the same pattern exists in the general pain population. Further, recent epidemiological research suggests chronic pain is independently associated with suicidality after controlling for demographic and mental health factors (Braden and Sullivan, 2008; Ilgen et al., 2013; Ratcliffe et al., 2008). 1National 2School
Drug and Alcohol Research Centre, UNSW, Sydney, Australia of Medicine, University of Tasmania, Hobart, Australia
Corresponding author: Gabrielle Campbell, National Drug and Alcohol Research Centre, UNSW, Sydney, NSW 2052, Australia. Email: [email protected]
Australian & New Zealand Journal of Psychiatry Downloaded from anp.sagepub.com at UNIV NEBRASKA LIBRARIES on March 16, 2015
2
ANZJP Articles
With an ageing population, and the likely increase in chronic pain, the issue of chronic pain and its relationship to suicidality is of timely importance. To our knowledge, there has been no study that has estimated the contribution that chronic pain may make to suicidality in the general population, and there are few existing data on the relationship between chronic pain and suicide in the Australian population. The aims of the current study were to: •• document the prevalence of chronic pain in Australia; •• examine lifetime and past 12-month suicidal behaviours in people with chronic pain, and estimate the contribution that a history of chronic pain may make to suicidality in the general population; •• determine whether chronic pain is associated with suicide when controlling for socio-demographic variables and mental health diagnoses; •• determine the risk factors for the past 12-month suicidal behaviours amongst people with chronic pain.
Method Sample Data from the Confidentialised Unit Record File (CURF) for the Australian 2007 National Survey of Mental Health and Wellbeing (NSMHWB) (Slade, et al., 2009) were obtained from the Australian Bureau of Statistics (ABS). The 2007 NSMHWB was conducted by trained interviewers from the ABS between August and December of 2007. The aim of the survey was to provide representative estimates on a national level. The 2007 NSMHWB sample was based on a stratified, multistage area probability sample of people aged 16–85 years in rural and urban private dwellings across all Australian States and Territories. The area-based selection ensured that all sections of the population living in private dwelling within the geographical scope of the survey were represented, representing a total of 17,352 dwellings. Special dwellings (hospitals, nursing homes, gaols, hotels) and dwellings in remote and sparsely settled regions of the country were not sampled, which reduced the effective sample size to 14,805 dwellings. All interviews were conducted in English, meaning that non-English speakers were excluded from the sample. Each interview was conducted in person and took approximately 90 minutes to complete. There were 8841 fully responding participants, which represented a rate of 60%. Owing to the lower than expected response rate (it was expected that a 75% response rate would be achieved), extensive non-response analyses were undertaken to assess the reliability of the survey estimates. A purposive sample of fully non-responding households in two metropolitan areas, Sydney and Perth, was followed up with a short-form interview, to gain a qualitative assessment of non-response bias. The study indicated the impact of non-response to be small at the aggregate level, but possible underestimation of the prevalence of mental disorders
may exist for men, young persons and the Perth population. The final sample represented an estimated population count (EPC) of 16,015,000 Australian adults. For further information about the procedure and instrument see Slade et al., (2009).
Survey The 2007 NSMHWB was based on the World Mental Health Survey Initiative version of the Composite International Diagnostic Interview (WMH-CIDI) (Kessler and Ustun, 2004). This interview has undergone extensive methodological development and testing and has been used in household surveys in at least 28 countries around the world. This version of the instrument collects both diagnostic information on a broad range of mental disorders and information on risk factors, impacts, patterns and treatment of mental disorders. There were some modifications made to the WMH-CIDI to tailor the survey to the Australian context. The following questions and measures from the 2007 NSMHWB were used in the current study. Chronic pain. The chronic conditions section was based on the WMH-CIDI chronic conditions module. The information provided is self-reported by the respondent and is not verified by a medical practitioner. The current study used questions that related to the presence of arthritis, migraines and back/neck pain that had persisted for a period of 6 months. A combined category of ‘any pain’ was created on the basis of endorsement of any one chronic pain condition (arthritis/migraines, back/neck problems). Socio-demographics. Consistent with Ratcliffe et al., (2008), age was split into categories of
