Psychometric evaluation of an adapted version of the perceived stress scale for ecological momentary assessment research.

Ecological momentary assessment (EMA) methodologies are commonly used to illuminate the predictors and impacts of experiencing subjective stress in the course of daily life. The validity of inferences from this research is contingent on the availability of measures of perceived momentary stress that can provide valid and reliable momentary stress scores. However, studies of the development and validation of such measures have been lacking. In this study, we use an EMA data collection design to examine the within- and between- person reliability and criterion validity and between-person gender measurement invariance of a brief EMA-adapted measure of a widely used trait measure of stress: the Perceived Stress Scale (PSS). Scores showed high internal consistency reliability and significant correlations with a range of criterion validity measures at both the within- and between-person level. Gender measurement invariance up to the scalar level also held for scores. Findings support the use of the EMA-adapted PSS presented in the current study for use in community-ascertained samples to address research questions relating to the influences on and effects of momentary stress and their gender differences.

Prompt-level predictors of compliance in an ecological momentary assessment study of young adults' mental health.

BACKGROUND: Ecological momentary assessment (EMA) has become a popular method of gathering information about participants as they go about their daily lives. However, participant non-compliance, especially non-random compliance, in EMA is a concern. Better knowledge of the moment-to-moment factors that predict prompt non-response can inform the design of strategies to mitigate it. METHOD: We used data from a general population young adult (n = 260) EMA study, 'decades-to-minutes' (D2M) and fitted dynamic structural equation models (DSEMs) to explore a range of candidate momentary predictors of missing the next prompt. RESULTS: We found that higher levels of stress, overall negative affect, and the specific negative affective state of 'upset' at a given prompt predicted a greater likelihood of missing the next prompt. However, no other specific affective states, alcohol use, experiencing social provocations nor aggressive behaviour predicted missing the next prompt. LIMITATIONS: The primary limitation of the present study was a lack of information on predictors concurrent with missed prompts. CONCLUSIONS: Findings point to the potential value of gathering information on momentary negative affect (especially feeling upset) and stress to help inform strategies that intervene to prevent application disengagement at optimal moments and to feed into strategies to mitigate bias due to non-random non-response in EMA studies.