An estimated 4.0% and 3.8% of the global population suffer from depressive and anxiety disorders, respectively (Institute for Health Metrics, 2019). These disorders often co-occur and both are associated with somatoform disorders, which lack an identifiable pathological basis but are commonly seen in routine clinical practice (Shidhaye et al., 2013). The prevalence and presentation of these common mental disorders (CMD), i.e., anxiety, depression, and somatic disorders, vary across age groups and cultures, but women are consistently more likely than men to report each disorder (Kiely et al., 2019; Riecher-Rössler, 2017; Seedat et al., 2009).
Excluding headache disorders, more than 20% of persons aged 60 years and over experience a mental or neurological disorder, and these disorders account for 6.6% of Disability Adjusted Life Years and 17.4% of Years Lived with Disability (WHO, 2017). Persons in this age group also represent about a quarter of deaths from self-harm, and those aged 85 and over have the highest suicide rates of any age group. Yet, despite the high prevalence and burden of CMDs in later life, detection rates are lower than for all other age groups, and only one in three persons aged 60 and over with a mental disorder receives the treatment they need.
To determine which older adults are not reaching needed mental health services and why this is the case requires a better understanding of this treatment gap (Werlen et al., 2020). Factors that contribute to low detection rates pervade societies and care systems and include stigma and ageism, low mental health literacy, and lack of access to effective, appropriate care (Bor, 2015). Another barrier to timely, accurate detection is the vast array of assessment and outcome measures that are in use (Boyce et al., 2021). The need for efficient, psychometrically sound, culturally appropriate measures of CMDs within and among populations is especially pressing in low-resource settings. To address this gap, Harding et al. (1980) developed the Self-Reporting Questionnaire (SRQ) in collaboration with the WHO, which later endorsed it as a universally applicable case-finding instrument for probable CMD in primary care settings in less developed countries (Beusenberg & Orley, 1994). Studies on the performance of the SRQ in different populations and settings have since reported different factor structures and mixed findings on gender differences. There is very little research with Latin American populations, and we found only one study, set in Brazil, that reported exclusively on older adults (Scazufca et al., 2014).
The current study aims to: 1) examine the factor structure of the 20-item version of the SRQ (SRQ-20) with older adults in Puerto Rico two years after a calamitous hurricane and during the COVID-19 pandemic and 2) explore measurement-related gender differences in the instrument’s performance with this population. We begin with a brief overview of the study context, the data source, and the sample. We then describe the SRQ-20 and, following Boyce et al. (2021), we justify our selection of this instrument as a mental health assessment and outcome measure with the study population and our focus on gender as an important source of measurement-related variance. We then present our findings and conclude with discussion and implications for using the SRQ-20 to improve the detection of CMDs among older adults in low-resource settings, notably in the Caribbean and other parts of Latin America.
Study Context
Puerto Rico, an unincorporated territory of the United States, is a member of the United Nations Economic Commission for Latin America and the Caribbean (ECLAC)--one of five regional commissions established in 1948 to work with regional governments to raise standards of living and strengthen trade relations elsewhere in the world. It is the island most impacted by hurricanes in the Caribbean. Economic, political, and social contexts of natural and human-made disasters profoundly affect damage and recovery, including health and mental health outcomes of residents (Benedek et al., 2007). In the months leading up to Hurricane María in September 2017, a decade-long economic recession forced Puerto Rico into bankruptcy (Brown, 2017). In July 2019, the governor was ousted for scandal and corruption and late that year and into early 2020, major earthquakes wracked the island. Within 6 months of the hurricane, an estimated 2,975 people, mostly older adults, had died (Santos-Burgoa et al., 2018) and nearly 200,000, mostly working-age adults and families, had migrated to the U.S. mainland. Between 2017 and 2020, the population declined from 3.16 million to 2.86 million (10%) and the median age rose from 39.2 to 44.5 years (Worldometer, 2021); fully 23.5% of the population is now aged 65 or over (U.S. Census Bureau, 2023).
In this context, the first case of COVID-19 in Puerto Rico was detected in March, 2020. The pandemic disproportionately affected Latinos, older adults, and persons with chronic health conditions (Garcia et al., 2021). However, Puerto Rico’s government implemented early, aggressive public health measures and by May 2022, 83.7% of the population was fully vaccinated and 95.7% had received at least one dose of vaccine (Centers for Disease Control and Prevention, 2021). The rapid succession of these devastating events, coupled with severe U.S. restrictions on aid to the island (U.S. Government Accounting Office, 2020) created new and worsened existing mental health risks for older adults.
The Self-Reporting Questionnaire (SRQ-20)
The full SRQ consists of 25 items derived from four psychiatric morbidity measures that are used across a wide range of cultural settings: 20 items assess neurotic symptoms, 4 measure psychotic symptoms, and 1 evaluates convulsions. The SRQ-20 comprises the neurotic items, which assess depressive symptoms, anxiety, and psychosomatic complaints during the past 30 days. Items are scored ‘yes’ (symptom present = 1) or ‘no’ (no symptom present = 0), then summed. In a systematic review of assessment instruments for CMDs in low resource settings, Ali (2016) recommended the SRQ-20 because of its ease of administration, broad applications, and extensive psychometric testing. The instrument has also been used to assess CMDs in the immediate and long-term aftermath of disasters (Stratton et al., 2014).
The SRQ-20 has been widely validated in primary care, community screening, and epidemiological population surveys and in multiple languages and cultural settings. It was developed as a unitary measure of CMDs, but studies report multifactor structures ranging from 2 to 7 factors, depending on context and cultural understanding of scale items (Scholte et al., 2011; Ventevogel et al., 2007). Consistent with the SRQ’s original intent, studies that report 3 or more factors regularly describe components that reflect depressive, anxiety and / or somatoform symptoms (Chen et al., 2009; Harpham et al., 2003). Similarly, while a cut-off score of 7 / 8 is often used to indicate probable mental disorder (Harpham et al.), optimal clinical thresholds vary by population characteristics, especially gender (WHO, 2002). Table 1 summarizes the performance of the SRQ-20 with adults in different populations and settings, showing different factor structures and mixed findings on gender-related measurement invariance.
Table 1
Factor Structure and Gender-Related Findings on the SRQ-20
Authors | Sample | Analysis | Reliability | Factor Domains | Implications |
Chen et al. [24] | China Primary Care N = 959 Community N = 60 Age: 18–64 56% female | PCA | Primary care α = .90 α = .93 (test-retest) Community α = .91 α = .94(test-retest) | 1. Depression 2. Anxiety 3. Somatic symptoms | SRQ-20 is a reliable, valid measure of CMD. |
Chipimo & Fylkesnes [46] | Zambia Primary care N = 400 Age: 16–67 58% female | PCA | - | 1. Common disorders 2. Social disability | SRQ20 is a valid tool. Must consider context. |
Hanlon et al. [31] | Ethiopia Primary care N = 306 Age unspecified 62% female | EFA | α = .90 | 1 factor model | Advantage of SRQ20 is routine item on suicidal ideation. |
Kootbodien et al. [23] | South Africa Community N = 360 Age: 18+ 37.1 (14.1) 58% female | CFA: Tested 1, 2, 3 factor models Tested gender invariance on 1 factor model | α = .84 Males, α = .81 Females, α = .84 | 1 factor model 2 factor model 1. Depression 2. Somatic symptoms 3 factor model: 1.Depression /anxiety 2.Hopelessness 3.Decreased energy | All 3models fit data well. No gender invariance SRQ-20 may perform better with women than men. |
Netsereab et al. [47] | Eritrea Primary care N = 266 Age: 32 (11.1) Range18-65 55% female | PCA | α = .78 | 2 factor model: Items specified Factors not labeled | SRQ-20 performs well. |
Rasmussen et al. [48] | Afghanistan Community N = 1003 Age: 35.1 (6.6) 50% female | EFA CFA | - | 3 factors: 1. Somatic complaints 2. Negative affect 3. Emotional numbing | Transcultural validation of mental distress measures must consider gender |
Scholte et al. [21] | Rwanda Intervention N = 418 Age: 16–87 61% female in baseline sample | EFA CFA | Male α = .81 Female α = .85 | 5 factors: 1. Emotional/ bodily symptoms depression 2. Disability 3. Digestive complaints 4. Lack energy 5. Self-esteem | SRQ-20 effective for screening Factor structure is time invariant |
Stratton et al. [29] | Vietnam Community N = 4,980 Age: 18–96 Mean = 41.5 SD = 16.3 54% female | EFA CFA Latent variable modeling | α = .84 | Bi-factor model: 1. General distress vs. 2. Subdomains of negative affect; somatic complaints; hopelessness Correlated 3 factor model: 1. Negative affect 2. Somatic complaints 3. Hopelessness | Bi-factor model fit data as well or better than 3-factor model. Different item endorsement for males and females |
van der Westhuizen et al. [37] | South Africa Emergency care N = 200 Age: 18+ 33% female | PCA | α = .84 | Overall Sample: 2 Factors: 1. Depression and anxiety 2. Somatic symptoms Males: 1. Depression; somatic symptoms 2. Anxiety; depression Females: 1. Depression; anxiety 2. Somatic symptoms 3. Lethargy | Different factor structure for males and females. SRQ-20 is useful for emergency settings in South Africa. |
Ventevogel et al. [22] | Afghanistan Primary care N = 116 Age: 17–80 54% female | EFA | - | 2 factors: 1. Common disorders 2. Social disability | No gender differences. Culture key to gender-related measurement |
Note. PCA = principal component analysis EFA = exploratory factor analysis CFA = confirmatory factor analysis |
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There is very little research on use of the SRQ-20 with Latin American and/or older adult populations. We identified only one validation study using the Spanish-language SRQ-20, set in Colombia (Fischer et al., 2019) and one with older adults, in Brazil (Scazufca et al., 2014) -- a sample in Vietnam [Richardson et al., 2010) did include older adults. We did not identify any psychometric studies using the Spanish version of the SRQ-20 with older adults. The current study thus aims to: 1) assess the factor structure of the 20-item SRQ (SRQ-20) with older adults in Puerto Rico, and 2) explore measurement-related gender differences in the instrument’s performance with this population.