The 1945 World Health Organization definition of health as a “complete state of physical, mental, and social wellbeing and not merely the lack of disease or disability” (WHO, 1945) implies that any holistic measurement of health should incorporate the physical, mental, and social dimensions of health. Evaluating the health of a specific population can provide necessary data to design and budget for health promotion and disease prevention efforts, as well as for planning for adequate health care for that population.
Physical health in individuals with schizophrenia has received substantial interest in recent years. According to the Lancet Psychiatry Commission (Firth etal., Reference Firth2019), nearly 100 systematic reviews/meta-analysis have examined the prevalence of physical comorbidities in mental illness, and literature consistently shows that individuals with serious mental illness (SMI), including schizophrenia, are associated with 1.4–2 fold increased risk of obesity, diabetes, and cardiovascular diseases compared to the general population (Firth etal., Reference Firth2019). This highlights the need for validated measures of overall physical health in individuals with schizophrenia, particularly measures that can be included conveniently as part of a variety of studies.
Given the practical challenges of measuring such a complex concept as “health,” Self-Rated Health (SRH) has attracted a lot of attention and is well-positioned to account for the associated multiple layers of complexity, especially in the elderly (Ocampo, Reference Ocampo2010). SRH is a widely accepted, reliable measure of overall health and has been demonstrated to be significantly associated with a population’s healthcare needs, both as an aggregate to determine public health needs and on an individual basis to screen for high-risk individuals early in the course of declining health. Given the broad benefits of SRH as a global measure of health status, it is important to determine its validity within various cohorts so as not to assume the validity of the measure where none may exist.
In their paper “The Utility of Self-Rated Health in Older Adults with Schizophrenia,” Cohen etal. (Reference Cohen, Vengassery and Reinhardt2019) sought to evaluate the utility of a single-item SRH measure in adults over the age of 55 with schizophrenia, as compared to their age-matched peers in the community. While SRH is widely used in geriatrics research as an easily collected global marker for global health, which is associated with survival, overall functional, morbidity, and health service utilization, its utility as a predictor of physical health and its associations with other variables of interest have not been well-established in older adults with schizophrenia (OAS). This study by Cohen etal., therefore, fills an important knowledge gap with regards to the use of SRH in OAS.
In this study, Cohen etal. recruited OAS from outpatient clinics, day programs, and supported community residences. All members of the OAS were aged 55 and over and had met the criteria for the diagnosis of schizophrenia or schizoaffective disorder prior to the age of 45, as assessed by clinical agency staff and by a lifetime illness review. The study excluded from the OAS group any potential study participants whose cognitive impairment was too severe to complete the questionnaire. Thirty-nine percent of the OAS group lived independently in the community and 61% lived in supported community residences. The community comparison (CC) group of persons aged 55 and over was recruited using block census data via door knocking, outreach through houses of worship and senior centers, and through personal references.
All subjects were asked to rate their health with the dependent variable being the subject’s response to the question “How would you rate your overall health at the present time?” A big strength of the study is that it was designed around Ocampo’s (Reference Ocampo2010) theoretical model of factors affecting SRH in the elderly. The authors consolidated Ocampo’s predictors into five dimensions: sociodemographic, biological, psychiatric, functional, and health perception of past self (temporal comparison) and age peers (social comparison). These dimensions were then examined using 12 variables. These included variables derived from the Positive and Negative Syndrome Scale (PANSS; Kay etal., Reference Kay, Opler and Fiszbein1992); Dementia Rating Scale (DRS; Coblentz etal., Reference Coblentz, Mattis, Zingesser and Peck1973); Center for Epidemiological Studies-Depression Scale (CES-D; Radloff, Reference Radloff1977); Community Integration Scale (Abdallah etal., Reference Abdallah, Cohen, Sanchez-Almira, Reyes and Ramirez2009); and the Multilevel Assessment Inventory and the Physical Self-Maintenance Scale (Lawton etal., Reference Lawton, Moss, Fulcomer and Kleban1982).
Cohen etal. determined that 6 of the 12 variables in their model significantly correlated with SRH in both OAS and community controls. Three of these variables, CES-D score, number of physical disorders, and perception of self-health versus others, remained significantly associated with SRH after linear regression analysis in both groups. These results, therefore, support the use of SRH as a valid clinical and research measure in OAS.
In other analyses in the study, there were no significant differences in SRH, possible alcohol misuse, number of physical illnesses, heart disease, diabetes, hypertension, difficulty with ambulation, number of medical visits to physicians over the past year, mean number of nonpsychiatric medications, and functional health status among the two groups. In the OAS group, neither PANSS positive nor PANSS negatives scores were significantly associated with SRH, nor was it a measure of psychiatric illness awareness.
With regards to the association between depression and SRH, the authors note that this finding is consistent with prior literature in which depression in older adults appears to diminish more favorable self-perceptions of health. This relationship between depression and subjective perception of health should be interpreted in light of the knowledge that the relationship between depression and physical health extends beyond mere alteration of perception: depression is also associated with a wide range of comorbid physical conditions as well as multiple levels of physical comorbidity (Smith etal., Reference Smith2014).
Similar to SRH, another single-item Self-Rated Mental Health (SRMH) measure has been shown to be moderately correlated with SRH in individuals with schizophrenia (Maguire etal., Reference Maguire, Reay and Raphael2016). This further emphasizes the relationship between mental health and physical health. Maguire etal. (Reference Maguire, Reay and Raphael2016) reported that for individuals with schizophrenia, SRMH can predict psychological levels of distress, illness perception – including perceived personal control over the illness, and anxiety and depression symptoms; as well as self-rated general health. This suggests that a future line of inquiry may be to determine the relationship between SRH and SRMH in OAS.
As the authors conclude, the use of a convenience sample for the OAS group does limit the generalizability of this study’s findings. Those OAS who are completely disengaged with treatment, whose disease severity requires inpatient hospitalization, and those whose symptoms are so mild as to be managed outside of these outpatient programs and supported housing are likely to be significantly underrepresented within the OAS group.
The authors set the age of onset for the OAS group as <45 years of age. While this exclusion of individuals with late-onset schizophrenia likely reduces the heterogeneity of the sample in terms of disease onset (and associated prognosis), this impacts the study further in terms of generalization since a substantial number of individuals with OAS have late-onset schizophrenia (Meesters etal., Reference Meesters2012). It is also worth noting that the mean PANSS score in the OAS was 53.5, which corresponds to “mild” illness (Leucht etal., Reference Leucht, Kane, Kissling, Hamann, Etschel and Engel2005). Although this is to be expected for a community sample of OAS, this does bring up uncertainties with regards to self-perception of health in individuals with more severe psychosis.
From a population health perspective, SRH can help determine the level of health care needs within a community and could conceivably be used to inform a multitude of public health initiatives. Given that is a single-item, SRH can also be conveniently added to a wide variety of research studies and increase our understanding of the relationships of SRH. Individuals struggling with SMI, including OAS, have higher rates of mortality and reduced life expectancy, with deaths from common physical illnesses, as compared with the non-SMI population (Lawrence and Kisely, Reference Lawrence and Kisely2010). Thus, one would expect there to be differences in overall physical health, and reflected in SRH, between OAS and community controls, given the disproportionate morbidity and mortality of cardiovascular and metabolic illness in schizophrenia. Hence, it is surprising that the SRH and physical health parameters were generally fairly similar between the OAS and CC groups in this particular study. One wonders if sample selection may have played a role in these findings.
In their recent study of disparity within the SMI population, Evans etal. highlight that roughly 60% of the SMI population does not regularly access mental health care. Their research shows that those with SMI in a minority racial or ethnic group, who are elderly, who identify as women, who live in rural areas, who identify as lesbian, gay, bisexual, and transgender (LGBT), and for whom English is the second language are underrepresented in studies of the SMI population (Evans etal., Reference Evans2016).
It is heartening to see a study that addresses the validity of SRH within an elderly population with a diagnosis of schizophrenia, and we commend Cohen etal. on this valuable addition to geriatric psychiatry literature. For future studies, we would encourage researchers to attempt to also include OAS who are typically underrepresented in such research, i.e. OAS with greater severity of psychotic symptoms, OAS with medical comorbidities, and OAS in the community who are not actively engaged in mental health treatment.
This commentary also provides us with an opportunity to look at recent research published in International Psychogeriatrics emphasizing the integration of mental, physical, and cognitive health of individuals with schizophrenia. For instance, González-Pablos etal. (Reference González-Pablos, Sanguino-Andrés, López-Villalobos, Iglesias-Santa Polonia, Hoyos-Villagrá and González-Sanguino2019) have discussed cognitive dysfunction in schizophrenia and its relationship with aging and cerebrovascular disease. Baruth etal. (Reference Baruth, Ho, Mohammad and Lapid2020) have examined how individuals with schizophrenia are subject to healthcare disparities and inequities in end-of-life care. Smeets-Janssen etal. (Reference Smeets-Janssen, Aderka, Meesters, Lange, Schouws and Rhebergen2020) have reported that in older schizophrenia patients, early- and late-onset ages form a continuum, with data showing one normally distributed population. Schuster etal. (Reference Schuster, Hoertel, von Gunten, Seigneurie and Limosin2020) have revealed that benzodiazepine use among OAS spectrum disorder is associated with medical comorbidities as well as cognitive and social functioning impairments. All these studies and many others highlight the intertwined nature of mental and physical health in schizophrenia, and the study by Cohen etal. (Reference Cohen, Vengassery and Reinhardt2019) bears further testimony to that.
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The 1945 World Health Organization definition of health as a “complete state of physical, mental, and social wellbeing and not merely the lack of disease or disability” (WHO, 1945) implies that any holistic measurement of health should incorporate the physical, mental, and social dimensions of health. Evaluating the health of a specific population can provide necessary data to design and budget for health promotion and disease prevention efforts, as well as for planning for adequate health care for that population.
Physical health in individuals with schizophrenia has received substantial interest in recent years. According to the Lancet Psychiatry Commission (Firth etal., Reference Firth2019), nearly 100 systematic reviews/meta-analysis have examined the prevalence of physical comorbidities in mental illness, and literature consistently shows that individuals with serious mental illness (SMI), including schizophrenia, are associated with 1.4–2 fold increased risk of obesity, diabetes, and cardiovascular diseases compared to the general population (Firth etal., Reference Firth2019). This highlights the need for validated measures of overall physical health in individuals with schizophrenia, particularly measures that can be included conveniently as part of a variety of studies.
Given the practical challenges of measuring such a complex concept as “health,” Self-Rated Health (SRH) has attracted a lot of attention and is well-positioned to account for the associated multiple layers of complexity, especially in the elderly (Ocampo, Reference Ocampo2010). SRH is a widely accepted, reliable measure of overall health and has been demonstrated to be significantly associated with a population’s healthcare needs, both as an aggregate to determine public health needs and on an individual basis to screen for high-risk individuals early in the course of declining health. Given the broad benefits of SRH as a global measure of health status, it is important to determine its validity within various cohorts so as not to assume the validity of the measure where none may exist.
In their paper “The Utility of Self-Rated Health in Older Adults with Schizophrenia,” Cohen etal. (Reference Cohen, Vengassery and Reinhardt2019) sought to evaluate the utility of a single-item SRH measure in adults over the age of 55 with schizophrenia, as compared to their age-matched peers in the community. While SRH is widely used in geriatrics research as an easily collected global marker for global health, which is associated with survival, overall functional, morbidity, and health service utilization, its utility as a predictor of physical health and its associations with other variables of interest have not been well-established in older adults with schizophrenia (OAS). This study by Cohen etal., therefore, fills an important knowledge gap with regards to the use of SRH in OAS.
In this study, Cohen etal. recruited OAS from outpatient clinics, day programs, and supported community residences. All members of the OAS were aged 55 and over and had met the criteria for the diagnosis of schizophrenia or schizoaffective disorder prior to the age of 45, as assessed by clinical agency staff and by a lifetime illness review. The study excluded from the OAS group any potential study participants whose cognitive impairment was too severe to complete the questionnaire. Thirty-nine percent of the OAS group lived independently in the community and 61% lived in supported community residences. The community comparison (CC) group of persons aged 55 and over was recruited using block census data via door knocking, outreach through houses of worship and senior centers, and through personal references.
All subjects were asked to rate their health with the dependent variable being the subject’s response to the question “How would you rate your overall health at the present time?” A big strength of the study is that it was designed around Ocampo’s (Reference Ocampo2010) theoretical model of factors affecting SRH in the elderly. The authors consolidated Ocampo’s predictors into five dimensions: sociodemographic, biological, psychiatric, functional, and health perception of past self (temporal comparison) and age peers (social comparison). These dimensions were then examined using 12 variables. These included variables derived from the Positive and Negative Syndrome Scale (PANSS; Kay etal., Reference Kay, Opler and Fiszbein1992); Dementia Rating Scale (DRS; Coblentz etal., Reference Coblentz, Mattis, Zingesser and Peck1973); Center for Epidemiological Studies-Depression Scale (CES-D; Radloff, Reference Radloff1977); Community Integration Scale (Abdallah etal., Reference Abdallah, Cohen, Sanchez-Almira, Reyes and Ramirez2009); and the Multilevel Assessment Inventory and the Physical Self-Maintenance Scale (Lawton etal., Reference Lawton, Moss, Fulcomer and Kleban1982).
Cohen etal. determined that 6 of the 12 variables in their model significantly correlated with SRH in both OAS and community controls. Three of these variables, CES-D score, number of physical disorders, and perception of self-health versus others, remained significantly associated with SRH after linear regression analysis in both groups. These results, therefore, support the use of SRH as a valid clinical and research measure in OAS.
In other analyses in the study, there were no significant differences in SRH, possible alcohol misuse, number of physical illnesses, heart disease, diabetes, hypertension, difficulty with ambulation, number of medical visits to physicians over the past year, mean number of nonpsychiatric medications, and functional health status among the two groups. In the OAS group, neither PANSS positive nor PANSS negatives scores were significantly associated with SRH, nor was it a measure of psychiatric illness awareness.
With regards to the association between depression and SRH, the authors note that this finding is consistent with prior literature in which depression in older adults appears to diminish more favorable self-perceptions of health. This relationship between depression and subjective perception of health should be interpreted in light of the knowledge that the relationship between depression and physical health extends beyond mere alteration of perception: depression is also associated with a wide range of comorbid physical conditions as well as multiple levels of physical comorbidity (Smith etal., Reference Smith2014).
Similar to SRH, another single-item Self-Rated Mental Health (SRMH) measure has been shown to be moderately correlated with SRH in individuals with schizophrenia (Maguire etal., Reference Maguire, Reay and Raphael2016). This further emphasizes the relationship between mental health and physical health. Maguire etal. (Reference Maguire, Reay and Raphael2016) reported that for individuals with schizophrenia, SRMH can predict psychological levels of distress, illness perception – including perceived personal control over the illness, and anxiety and depression symptoms; as well as self-rated general health. This suggests that a future line of inquiry may be to determine the relationship between SRH and SRMH in OAS.
As the authors conclude, the use of a convenience sample for the OAS group does limit the generalizability of this study’s findings. Those OAS who are completely disengaged with treatment, whose disease severity requires inpatient hospitalization, and those whose symptoms are so mild as to be managed outside of these outpatient programs and supported housing are likely to be significantly underrepresented within the OAS group.
The authors set the age of onset for the OAS group as <45 years of age. While this exclusion of individuals with late-onset schizophrenia likely reduces the heterogeneity of the sample in terms of disease onset (and associated prognosis), this impacts the study further in terms of generalization since a substantial number of individuals with OAS have late-onset schizophrenia (Meesters etal., Reference Meesters2012). It is also worth noting that the mean PANSS score in the OAS was 53.5, which corresponds to “mild” illness (Leucht etal., Reference Leucht, Kane, Kissling, Hamann, Etschel and Engel2005). Although this is to be expected for a community sample of OAS, this does bring up uncertainties with regards to self-perception of health in individuals with more severe psychosis.
From a population health perspective, SRH can help determine the level of health care needs within a community and could conceivably be used to inform a multitude of public health initiatives. Given that is a single-item, SRH can also be conveniently added to a wide variety of research studies and increase our understanding of the relationships of SRH. Individuals struggling with SMI, including OAS, have higher rates of mortality and reduced life expectancy, with deaths from common physical illnesses, as compared with the non-SMI population (Lawrence and Kisely, Reference Lawrence and Kisely2010). Thus, one would expect there to be differences in overall physical health, and reflected in SRH, between OAS and community controls, given the disproportionate morbidity and mortality of cardiovascular and metabolic illness in schizophrenia. Hence, it is surprising that the SRH and physical health parameters were generally fairly similar between the OAS and CC groups in this particular study. One wonders if sample selection may have played a role in these findings.
In their recent study of disparity within the SMI population, Evans etal. highlight that roughly 60% of the SMI population does not regularly access mental health care. Their research shows that those with SMI in a minority racial or ethnic group, who are elderly, who identify as women, who live in rural areas, who identify as lesbian, gay, bisexual, and transgender (LGBT), and for whom English is the second language are underrepresented in studies of the SMI population (Evans etal., Reference Evans2016).
It is heartening to see a study that addresses the validity of SRH within an elderly population with a diagnosis of schizophrenia, and we commend Cohen etal. on this valuable addition to geriatric psychiatry literature. For future studies, we would encourage researchers to attempt to also include OAS who are typically underrepresented in such research, i.e. OAS with greater severity of psychotic symptoms, OAS with medical comorbidities, and OAS in the community who are not actively engaged in mental health treatment.
This commentary also provides us with an opportunity to look at recent research published in International Psychogeriatrics emphasizing the integration of mental, physical, and cognitive health of individuals with schizophrenia. For instance, González-Pablos etal. (Reference González-Pablos, Sanguino-Andrés, López-Villalobos, Iglesias-Santa Polonia, Hoyos-Villagrá and González-Sanguino2019) have discussed cognitive dysfunction in schizophrenia and its relationship with aging and cerebrovascular disease. Baruth etal. (Reference Baruth, Ho, Mohammad and Lapid2020) have examined how individuals with schizophrenia are subject to healthcare disparities and inequities in end-of-life care. Smeets-Janssen etal. (Reference Smeets-Janssen, Aderka, Meesters, Lange, Schouws and Rhebergen2020) have reported that in older schizophrenia patients, early- and late-onset ages form a continuum, with data showing one normally distributed population. Schuster etal. (Reference Schuster, Hoertel, von Gunten, Seigneurie and Limosin2020) have revealed that benzodiazepine use among OAS spectrum disorder is associated with medical comorbidities as well as cognitive and social functioning impairments. All these studies and many others highlight the intertwined nature of mental and physical health in schizophrenia, and the study by Cohen etal. (Reference Cohen, Vengassery and Reinhardt2019) bears further testimony to that.
Conflicts of interest
None.