PHQ-9 and GAD-7 to detect depression and anxiety in healthcare workers with and without chronic diseases

Ansiedad y Estrés, (2025), 31(1), 8-14
https://doi.org/10.5093/anyes2025a2
https://www.ansiedadyestres.es
Bibliography reference

PHQ-9 and GAD-7 to detect depression and anxiety in healthcare workers with and without chronic diseases

INFO ARTICLE

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Received 20 September 2024
Accepted 8 January 2025

 

ABSTRACT

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Chronic diseases are highly prevalent and represent an important burden. Comorbidity between chronic diseases and emotional disorders is common, specially for people with comorbid depression and anxiety as they lead to a worsening of the prognosis. Although the Patient Health Questionnaire (PHQ) can provide an easy and inexpensive way to detect them, they often remain undetected. This study explores the prevalence of these conditions amongst hospital employees using a cross-sectional study (n = 1,075). Based on employee health care records, 89 of these people had some type of chronic physical condition. We then randomly selected 89 age- and sex-matched healthy individuals for comparison. All participants completed screening tools for depression (PHQ-9) and anxiety (GAD-7). Depression and anxiety rates were, respectively, 2.97 and 2.59 times higher (OR) in the chronic group, indicating that people with chronic conditions are especially sensitive to psychosocial risks. These findings underscore the need to routinely monitor the emotional health of workers for the early detection of emotional disorders and specially in the case of particularly sensitive workers, such as those with known chronic illnesses.

 

KEYWORDS

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Depression
Anxiety
Chronic diseases
Health surveillance
Mental health

Ansiedad y Estrés, (2025), 31(1), 8-14
https://doi.org/10.5093/anyes2025a2
https://www.ansiedadyestres.es
Bibliography reference

RESUMEN

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Las enfermedades crónicas son altamente prevalentes y representan una carga importante. La comorbilidad entre enfermedades crónicas y trastornos emocionales es común, especialmente en personas con depresión y ansiedad comórbidas, ya que empeoran el pronóstico. Aunque el Cuestionario de Salud del Paciente (PHQ) puede ofrecer una forma fácil y económica de detectarlas, a menudo permanecen sin ser identificadas. Este estudio explora la prevalencia de estas condiciones entre empleados de un hospital mediante un estudio transversal (n = 1,075). Según los registros de salud de los empleados, 89 de estas personas tenían algún tipo de condición física crónica. Luego, seleccionamos al azar 89 individuos sanos emparejados por edad y sexo para su comparación. Todos los participantes completaron herramientas de detección de depresión (PHQ-9) y ansiedad (GAD-7). Las tasas de depresión y ansiedad fueron, respectivamente, 2.97 y 2.59 veces más altas (OR) en el grupo crónico, lo que indica que las personas con condiciones crónicas son especialmente sensibles a los riesgos psicosociales. Estos hallazgos destacan la necesidad de monitorear rutinariamente la salud emocional de los trabajadores para la detección temprana de trastornos emocionales y sobre todo en los casos de trabajadores especialmente sensibles, como puede ser aquellos con enfermedad crónica conocida.

 

PALABRAS CLAVE

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Depresión
Ansiedad
Enfermedad crónica
Encuesta de salud
Salud mental
 

Introduction

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Chronic diseases are highly prevalent in the population and associated with extensive use of health care resources and non-health costs (Johnston et al., 2019). Anxiety and depression are two of the most commonly observed mental disorders among the working age population and these are closely associated with poor quality of life, higher disability, and morbidity rates, which can have an important negative impact on society. Published data show that these disorders can appear early in adulthood, leading to worsening physical health and work disability (Cano-Vindel, 2011). However, these disorders are often undiagnosed and untreated (Kessler, 2007). Mental disorders—mainly anxiety and depression—are estimated to account for 40% of disabilities (both physical and mental). By contrast, most chronic physical health conditions, such as cardiovascular disease, emerge later in life, particularly starting in the fifth decade of life onwards (Layard and Clark, 2015).

A report by the British government found that many people with chronic physical conditions also have these mental health problems. Comorbidity between physical and emotional disorders can significantly worsen the person’s health status and quality of life (Naylor et al., 2012), synergistically increasing the association with disability, such that the resulting odds ratio (OR) is greater than the sum of the ORs for each disorder (Scott et al., 2009). For example, depression is associated with excess mortality (OR=1.52) in patients with all types of physical illness (Cuijpers et al., 2014). So, comorbidity between physical disorders and depression is common and associated with high costs and worse self-care, treatment, and prognosis (Read et al., 2017) and anxiety symptoms in people with depression and multimorbidity signify worse health status (Felez-Nobrega et al., 2022). Multimorbidity with depression and anxiety disorders is a growing global public health challenge due to population aging and the consequent increase in the prevalence of chronic conditions (Scott et al., 2016, 2007). It is estimated that chronic conditions linked to poor mental health

account for 12% to 18% of all spending by the National Health Service (NHS) in England, with total estimated costs ranging from £8 to £13 billion every year (Naylor et al., 2012). The most conservative estimates suggest that there is about £1 of cost overrun for every £8 spent on chronic physical illness. The costs for the health system are also significantly higher, probably due to this synergistic interplay between emotional problems and chronic physical conditions, which exacerbates physical illness, thus raising the total costs of medical care by at least 45% for each person with a chronic condition and comorbid mental health problems (Naylor et al., 2012). However, in adults and older people, these mental disorders often go undetected and untreated (Devita et al., 2022; Scott et al., 2009).

Care for people with chronic conditions could be improved by providing better mental health support in the primary care (PC) setting, and by offering worker health surveillance and chronic disease management programmes in occupational health services (OHS). Providing better support for comorbid mental health care needs would reduce the costs of hospital care (Jeon and Kim, 2018).

Work stress is associated with common mental disorders (Clark et al., 2012) and certain chronic health problems, such as hypertension, coronary heart disease (Kivimäki et al., 2006; Xu et al., 2015), musculoskeletal problems (Melkevik et al., 2018), and diabetes (Cano-Vindel, 2011). Work stress is associated with mental disorders in both sexes and considered a risk factor for mental disorders and chronic use of antidepressants (Virtanen et al., 2007). Both mental and physical disorders are responsible for a high percentage of absenteeism, presenteeism, and work disability (Janssens et al., 2016; Munir et al., 2007). Globally, 15% of working-age adults were estimated to have a mental disorder in 2019 (World Health Organization, 2022). The impact of depression in the workplace is considerable across all countries, both in absolute monetary terms and in relation to proportion of country GDP and presenteeism is estimated to be 5–10 times higher than those

associated with absenteeism (Evans-Lacko and Knapp, 2016). The European Agency for the Safety and Health at Work (EU-OSHA) estimates that 50-60% of these disorders are attributable to stress and psychosocial factors and the associated costs are estimated to be substantial (ranging from 1% to 2% of gross domestic product [GDP], depending on the study). Even though the EU-OSHA consider risk prevention policies for psychosocial factors to be cost-effective (Hassard et al., 2014), only one-third of organisations in Spain and Europe have implemented these types of policies. The objective of occupational health is to protect and improve workers’ health by preventing and managing occupational disease (World Health Organization, 1994). In this regard, OHS can help to achieve early detection of cases in the working population. Despite the need for early detection of depression and anxiety in the workplace, there is a notably paucity of data on the use of validated instruments, designed to detect emotional disorders (Morawa et al., 2021).

Currently, several brief, reliable, and well-validated instruments are available to identify—with a high degree of sensitivity and specificity—possible cases of depression and/or anxiety. These instruments are commonly used in primary care, but they are also suitable for use in the workplace. For example, the application of these tools in health surveillance consultations could facilitate early detection of these disorders in individuals and groups. The Patient Health Questionnaire (PHQ) is probably among the most widely used screening test in primary care worldwide. The PHQ is based on DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, 4th edition) criteria and it has been validated in several countries. It is a brief tool—an important feature given the limited time available during PC consultations—with several subscales. Moreover, it is available for free online (https://www.phqscreeners.com/). The tool has several modules to assess the most common mental disorders including major depression (PHQ-9) (Kroenke et al., 2001) and generalized anxiety (GAD-7) (Spitzer et al., 2006). The Psychology in Primary Care (PsicAP) clinical

trial (Cano-Vindel et al., 2022) evaluated the psychometric properties of the PHQ-9 (Muñoz-Navarro et al., 2017a), the GAD-7 (Muñoz-Navarro et al., 2017b) and others like PHQ-PD (Muñoz-Navarro et al., 2016), to assess panic disorder, for use in the Spanish population. That same trial also evaluated the ultra-short 4-item version (PHQ-4) to assess for the presence of anxiety and depression in PC patients with a suspected emotional problem (Muñoz-Navarro et al., 2017c).

The PHQ and its subscales have been used in numerous studies due to their brevity, good psychometric properties, and utility (Muñoz-Navarro et al., 2017c). Nevertheless, there is a notable lack of published data on the value of these tools for the prevention of psychosocial risks, with few exceptions (Morawa et al., 2021). Healthcare workers have been vulnerable to adverse mental health impacts of the COVID-19 pandemic, and some study about the prevalence of mental disorders healthcare professionals in Spain and other countries using PHQ has been published (Alonso et al., 2021). Given this paucity of data on strategies for the early detection of depression and anxiety disorders, it is clear that research is needed on the application of evidence-based treatments for the management of emotional disorders in people with chronic physical conditions, as the treatment of comorbid emotional conditions would help to stabilize the chronic conditions (Cano-Vindel et al., 2022).

In this context, the purpose of the present study was to evaluate the value of offering brief, validated screening tests for depression and anxiety administered in the course of routine health surveillance by the OHS at our hospital. More specifically, we sought to evaluate the association between chronic diseases and depression and anxiety among workers at a tertiary public hospital by administering the PHQ-9 and GAD-7 screening questionnaires.

Methodology

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Procedure and participants

The study was carried out at a tertiary care hospital in Spain with a total of 5,485 employees. All employees were eligible to attend a health surveillance consultation offered by the hospital’s OHS between April and December 2022. All service users were asked to complete two self-administered screening questionnaires.

Of the workers who participated in the OHS consultation (n=1,075), 89 had been diagnosed with a chronic disease that required adaptation to their job. The highest percentage of major chronic diseases suffered was for severe musculoskeletal disorders. In all cases, the Prevention Service assessed the difficulties that the worker had in performing his/her job due to a particular pathology or the possible harm that could be caused by that pathology in performing all the functions assigned to him/her. This assessment was documented with a report on the adaptation, indicating the functional limits that apply in each case. For example, exemption from night work, no handling of loads, no prolonged walking, no raising of the arms above the shoulders, etc. The remaining 986 cases had no known chronic diseases. From these 986 individuals, 89 age- and sex-matched workers were randomly selected to participate in this study as control group.

All active hospital workers who voluntarily attended the health surveillance consultations were eligible for study inclusion.

Instruments

Two screening questionnaires were used, the PHQ-9 for depression and the GAD-7 for anxiety. Both are subscales of the PHQ, an instrument that has been validated in the Spanish population (Diez-Quevedo et al., 2001). A previous study carried out in a large group of participants (n=1000) showed high levels of sensitivity (90%) and specificity (90%) for these instruments. Both the PHQ-9 and the GAD-7 are considered screening tools because they are based on the DSM-IV diagnostic criteria, and in the Spanish versions, internal consistency for PHQ-9 was satisfactory (McDonald’s ? = .89), and good in the case of GAD-7 (? = .93). (González-Blanch et al., 2018; Moriana et al., 2022; Muñoz-Navarro et al., 2017a, 2017b). We selected a cut-off point of 10 on both scales (i.e., = 10) to obtain the best balance between sensitivity and specificity. Additionally, in the correction, the DSM rules were used, that is, the symptoms and conditions that must be met to assign a DSM diagnosis were considered (stricter and more precise criteria for making a probable diagnosis). Major Depressive Syndrome, if answers to #2a or 2b and five or more of #2a-2i are at least “More than half the days” (count #2i if present at all). General Anxiety Disorder or Other Anxiety Syndrome  if #5a and answers to three or more of  #5b-5g are “More than half the days”.

We also evaluated the following variables age; sex; self-reported presence of depression and/or anxiety symptoms; and chronic illness and job adaptation (based on data obtained from the participants’ employment records). Since there is a close relationship between the level of depressive symptoms and dysfunction measured in QALYs (quality-adjusted life years), we carried out an estimate of the loss of functionality that workers with higher symptoms of depression could suffer, based on the recommendations of Furukawa et al. (2021).

Ethical approval

This study fully complied with all provision of the Spanish Data Protection Law. The study protocol was approved by the institutional ethics committee at the Hospital Clínico San Carlos de Madrid (approval code: 23/099-E). The participants’ anonymity and data confidentiality were guaranteed. All data from the questionnaires was anonymized and grouped for the statistical analysis. Participants completed the PHQ-9 and GAD-7 questionnaires manually between April 4 and December 30, 2022.

Data Analysis

For quantitative variables, frequencies and percentages of possible emotional disorders were calculated and analysed using chi-square techniques, with a 95% confidence level (CI) and a sampling error of +/- 2.61%. In cases in which a statistically significant association was obtained, we also calculated ORs with 95% CI. The mean differences in depression and anxiety levels between groups were calculated and analysed using t-tests and Hedges g effect sizes. The differences between groups in level of depression in the PHQ-9 scores were translated into utilities in quality of life, following the equivalence indicated in a study that published the conversion table between the PHQ-9 and EQ-5D-3L (Rabin et al., 2015) scores or utilities (Furukawa et al., 2021). The EQ-5D offers a measure of self-perceived health that incorporates individual preferences (utilities) about health states and that serves as a measure of effectiveness in the economic evaluation of health technologies and health policies. The EQ-5D scores range between 1=full health and 0=death, or to minus values=worse than death, bounded by -1. These scores permit to calculate quality-adjusted life years or QALYs,

(QALYs = U x t, being U the utility, extracted from the EQ-5D, and t is time, in years, that the patient is in that utility). A full quality life year (utility = 1) can become as little as half quality-adjusted life years, or QALYs, when utility is 0.5.

Results

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A total of 1,075 individuals (19.6% of the hospital workforce) participated in the health surveillance program, whose depression, anxiety and physical health status (known chronicity and adaptation to the workplace) were evaluated. Of these, 178 were included in this study (89 with chronic illness and 89 healthy workers).

Most of the 178 study participants (n=166) were women (93.3%; 83 cases and 83 controls). The age range was between 18 and 68 years, with a mean age of 47.2 in the cases and 44.3 in controls (p<0.128). Table 1 shows the sociodemographic and clinical variables of the study participants.

INSERT TABLE 1 HERE

Symptoms of depression were more prevalent in the chronic group, with a mean (standard deviation [SD]) score of 8.22 (6.24) on the PHQ-9 vs 4.47 (5.57) in controls (t: 4.234; p<.0000; g: 0.63). The chronic group also presented significantly more anxiety symptoms, with a mean score of 8.00 (5.00) on the GAD-7 vs. 4.63 (5.04) in controls (t: 4.481; p< .0000; g: 0.67).

INSERT TABLE 2 HERE

The prevalence of suspected depression (cut-off score = 10 on the PHQ-9) was higher in the chronic group (Table 2), with 34 of the 89 participants scoring = 10 on the PHQ-9 (38.2%) versus only 14 (15.7%) in the controls (p<0.001). Similarly, a higher percentage of the chronic group also met DSM correction criteria for depression (n=18, 24.7% vs. n=7, 7.9%; p<0.029). This result would be very similar to a cut-off point of 14, instead of 10.

The prevalence of anxiety was also higher in the chronic group, with 33 individuals (37.1%) scoring = 10 on the GAD-7 vs. 12 (13.5%) in controls (p<0.000). Significant between-group differences were also found based on the DSM correction criteria (n=12 [13.5%] vs. n=10 [11.2%]; p<0.031). This result would be equivalent to a cut point of 11, instead of 10.

Based on the DSM-IV correction criteria of the two inventories, depression and anxiety were, respectively, 2.97 and 2.59 (OR, Table 2) times more likely in the chronic group versus the healthy controls without known chronic disease.

Amongst the workers with chronic conditions who tested positive on PHQ-9 (score = 10), scores in depression ranged from 10 to 24 (the maximum would be 27), indicating a wide range of depressive symptom intensity, which correspond to a similarly wide range of health utility (between 0.84 and 0.23) in EQ-5D-3L.The intensity of depressive symptoms was greater in the chronic group, who scored nearly four points higher than controls on the PHQ-9. This difference could imply an equivalent of loss of health benefits or quality of life of 0.08 compared to controls, according to the conversion table between the PHQ-9 and EQ-5D-3L scores (Furukawa et al., 2021).

Discussion

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The present study was performed to evaluate the presence of depression and anxiety in a sample of workers with and without chronic conditions at a tertiary care hospital. The data were obtained through self-administered screening questionnaires performed during routine health surveillance consultations organized by the hospital OHS. A group of 89 participants with chronic physical illnesses were compared to a randomly-selected age- and sex matched control group of healthy workers. The main findings of this study show that workers with chronic diseases are almost three times more likely to suffer from depression and/or anxiety.

Anxiety and depression are generally mild or moderate disorders. Despite the availability of effective treatments (Cano-Vindel et al., 2022), these disorders continue to impose a great burden on many people and on society as a whole due to underdetection. Despite the relatively high prevalence of these disorders in the general population and in health workers during the pandemic (Alonso et al., 2021), published reports describing the detection of these emotional disorders through routine health surveillance consultations carried out by OHS are scant, not even in high-risk groups such as workers with chronic physical illnesses.

The characteristics of the workers included in our study, both those with and without chronic physical conditions, are similar to those described in the 2021 European Health Survey in the general population (Instituto Nacional de Estadística (INE), 2020). In that survey, the mean prevalence of anxiety and depressive disorders was, respectively, 12.4% and 6.4%. In our study sample (n=1,075), we found similar rates for anxiety (12.3%) and slightly higher rates for depression (8.7%). In other words, the prevalence of emotional symptoms in our sample was similar to the observed in the general population, suggesting that working at a health care centre is not a risk factor for the development of emotional problems after the pandemic. That said, it is important to note worth emphasising that prevalence rates of depression and anxiety were significantly greater among workers with chronic conditions than their healthy counterparts.

In our sample, for workers with chronic diseases, it was found that about 20% met the diagnostic criteria for possible depressive disorder, almost 3 times more than workers without chronic illness, in line with other studies (Ould Brahim et al., 2021). On the other hand, workers with chronic diseases had more intense depressive symptoms than controls (PHQ-9 scores nearly 4 points higher than controls), which implies a loss of utility or health benefits or quality of life around 0.08 compared to controls. If we accept that the differences between groups would eventually be maintained over the course of a year, assuming that the group

with chronic physical conditions does not worsen further than the control group, despite the greater degree of depression plus physical chronicity, the difference in QALYs per year would equal 0.08 QALY, almost equivalent to 1 year of treatment with antidepressant pharmacotherapy or psychotherapy over the pill placebo condition (Furukawa et al., 2021). Workers with physical chronic conditions and positive PHQ-9 score (= 10) had a lower quality of life, that is, a significant decrease in quality-adjusted years lived, which is associated to a great impact, both in absolute monetary terms and in relation to proportion of country GDP, due especially to absenteeism and even more presenteeism in the workplace (Evans-Lacko and Knapp, 2016), but this loss of quality of life, and the associated disability, could be recovered by applying effective treatments (Furukawa et al., 2021), conducting self-management interventions on reducing depressive symptomatology in adults with chronic diseases and co-occurring depressive symptoms (Ould Brahim et al., 2021).

While is true that the presence of psychopathology (both depression and anxiety) was higher in the chronic group than in controls, being in the controls similar to the general population. Although these results indicate that working in a hospital is not associated with an increased

probability of depression or anxiety, however, psychosocial risks must be evaluated, as required by Spanish and European legislation. On the other hand, our findings highlighting that the presence of a chronic disease significantly increases the likelihood of depression and/or anxiety suggests that the OHS of organizations should screen for depression and anxiety in the course of routine monitoring of workers’ health. Similarly, these organisations should be aware that individuals with chronic diseases are especially sensitive to psychosocial risks.

This study has several limitations. First, although we used employment records to determine the presence of a chronic physical condition, detection of depression and anxiety was made through self-report measures, with the attendant limitations of such instruments.

Nonetheless, self-report tests are widely used today and numerous studies have shown that these instruments have good sensitivity and specificity that is only slightly inferior to semi-structured diagnostic interviews, which are much more time-consuming and expensive to administer. Another limitation was not having evaluated the possible existence of multimorbidity. Another limitation is the small number of males in the sample of workers with chronic illness and job adaptation. Although the percentage of sexes in both groups has been equalised to avoid comparison biases regarding chronicity, this makes it more difficult to generalise the results.

Despite these limitations, the study has several key strengths, including the application of screening tests in health surveillance consultations. Importantly, our findings demonstrate the utility of these tools to promote workers' health, especially in vulnerable groups such as those with chronic illness. Another strength is the size of the study sample, comprising nearly 20% of the organization’s total workforce. In this regard, the sample can be considered representative. Finally, this study demonstrates that screening can be conducted as part of the routine health surveillance consultations, without increasing costs. This is important, given the benefits obtained, allowing us to detect the current burden of depression, anxiety and chronic diseases in this sample.

Conclusion

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Depression and anxiety have a significant negative impact on quality of life in workers with chronical conditions. The findings of our study in terms of comorbidity between chronic physical illness and depression and/or anxiety in this working population are consistent with those described in the general population.

Our data show that both of these emotional disorders are highly prevalent in hospital workers with chronic physical conditions. Unfortunately, these disorders often remain undetected and/or inadequately treated, which can have important consequences, such as absenteeism, reduced productivity, presenteeism, higher medical care costs, and higher labour costs. For this reason, early detection and self-management interventions of depression and anxiety in

these workers are important to help reduce symptom duration and severity and to lower the costs associated with these conditions in the workplace and in other health and social settings.

The high prevalence of anxiety and depression in the workplace and in general population underscores the need to implement adequate surveillance programs to monitor the mental health status of workers in order to detect the presence of anxiety and depression. An important finding of this study is that workers with chronic disease are more susceptible to anxiety and depression, and can thus be considered especially sensitive to psychosocial risks, which further underscores the importance of performing routine mental health assessments in the workplace setting.

This study shows that evidence-based measures are needed to protect the functionality and mental health of people in the workplace in accordance with occupational risk prevention laws. The high prevalence of previously undetected anxiety and depression in our sample underscores the need to find ways to detect these issues without waiting for workers to request help. This study demonstrates that this can be achieved by administering screening questionnaires such as the PHQ-9 and GAD-7 in the course of routine health surveillance consultations organized by the OHS.

Funding source

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This work has been supported by a grant from the Agencia Estatal de Investigación to Antonio Cano-Vindel and (PID2019-107243RB-C21). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Declaration of competing interest

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The authors and the sponsor declare that the research will be conducted without any commercial or financial relationships that could be construed as a potential conflict of interest.

Acknowledgments

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We thank all the members of the OHS and workers of the Hospital Clínico San Carlos for their participation in this project.

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