Reliability and Factor Structure of the 10-item Kessler Psychological Distress Scale (K10) among Portuguese adults

Abstract

The 10-item Kessler Psychological Distress Scale (K10) has been presented as a valid measure to assess psychological distress levels in population surveys but its dimensional structure was not consensual. Our main objective was to provide a Portuguese version of the K10 exploring the reliability and factor structure of this measure. This cross-sectional study included 694 adults collected from a web-based survey and in training entities. Results showed that 37.9% of the individuals reported significant distress symptoms. A good internal consistency of the K10 scale (α=.91) and strong inter-item correlation (ranges from .350 to .659) were found in our study but the original one-dimensional structure was not confirmed. A two-factor model considering anxiety and depression as two latent, independent but correlated factors shows a good fit with the data even across two data collection methods. The K10 tool was sensitive to sociodemographic variables. Participants aged 40 or over and belonging to the general working class presented higher distress levels. Our data indicates the Portuguese version of K10 as a reliable tool with a factor structure to assess psychological distress.

Kessler Psychological Distress Scale: Internal Structure and Relation to Other Variables

“…As for the social distribution, mild to moderate distress rates were observed in the sample, which is close to the results found in validation studies of the scale with several populations (Easton et al, 2017;Pereira et al, 2017;Vasiliadis et al, 2015). Regarding the comparison of means between samples, other investigations found similar results to those in the present study (M = 19.3), namely: mean 21.7 points in a Palestinian sample (Easton et al, 2017), 20.5 points in Portuguese individuals (Pereira et al, 2017), 17.9 points in an Argentine population sample (Brenlla & Aranguren, 2010), 17.6 points in a Canadian sample (Vasiliadis et al, 2015), and 16.7 points in a rural random sample from Bangladesh (Uddin, Islam, & Al Mahmud, 2018). It is observed that there is similar evidence across all continents regarding distress, even in different populations and types of sample.…”

“…K10 was an instrument used in studies conducted in several countries, with different samples, such as South Africa (Andersen et al, 2011), Argentina (Brenlla & Aranguren, 2010), Australia (Anderson et al, 2013;Brooks, Beard, & Steel, 2006;Sunderland, Mahoney, & Andrews, 2012), Canada (Bougie et al, 2016;Caron et al, 2012;Sampasa-Kanyinga, Zamorski, & Colma, 2018;Vasiliadis, Chudzinski, Gontijo-Guerra, & Préville, 2015), the West Bank (Easton et al, 2017), Japan (Furukawa et al, 2010;Sakurai, Nishi, Kondo, Yanagida, & Kawakami, 2011), the Netherlands (Donker et al, 2010), Portugal (Pereira et al, 2017), Mexico (Terrez, Salcedo, Estrada, Romero, & Sotres, 2011), among others. Currently, K10 is translated into more than 15 different languages, having been validated in most of the countries where it is used (National Comorbidity Survey, n. d.).…”

Burnout and Stress Measurement in Police Officers: Literature Review and a Study With the Operational Police Stress Questionnaire

“…The fourth and last group of questions was composed from the Kessler Psychological Distress Scale (K10), from Kessler et al (2002Kessler et al ( , 2003. We used the Portuguese version by Pereira et al (2019), who described K10 as having 10 items that assess the frequency of non-specific psychological distress symptoms during the last month, being a self-report measure based on questions about the symptoms of anxiety and depression. All items are assessed on a 5-point scale (1 = "none of the time" to 5 = "all of the time") and the sum of the scores indicates the stress level, where high scores correspond to high stress levels.…”

“…Using this sum it is possible to identify cut-off points of stress levels, where 10-15 points correspond to "low distress, " 16-21 points to "moderate, " 22-29 points to "high, " and 30-50 points to "very high." Values between 22 and 50 points indicate a risk of developing a psychological disorder (Andrews and Slade, 2001;Pereira et al, 2019).…”

“…The Police Stress Questionnaire (McCreary and Thompson, 2006) is a short measure (20 items) allowing for the assessment of operational or organizational police stress, it is freely available for research purposes and has established stress levels with cut-off points. Since some studies used global measures of stress or stress symptoms, it was decided to also use the short questionnaire Kessler Psychological Distress Scale (K10), which has a recent Portuguese version (Pereira et al, 2019). Thus, this study can contribute to the development of a Portuguese version of a specific police stress instrument, and to identify stress and burnout levels of a sample of police officers using validated instruments.…”