Development and validation of the while-in-bed-smartphone-use-induced sleep procrastination scale (WSPS) in Chinese undergraduates with/without problematic smartphone use.

Purpose: Problematic smartphone use (PSU) has become a global public health problem. Excessive while-in-bed smartphone use may result in sleep procrastination and other negative outcomes. The present study aimed to develop and validate a new scale called WSPS to assess while-in-bed-smartphone-use-induced sleep procrastination among undergraduates.

Methods: In total, 910 Chinese undergraduates completed the collection of WSPS, smartphone addiction scale-short version (SAS-SV), bedtime procrastination scale, Pittsburgh sleep quality index, and Zung self-rating depression scale. The whole sample were randomly splited in the exploratory factor analysis (EFA) sample (n = 455) and confirmatory factor analysis (CFA) sample (n = 455). 40 undergraduates with PSU (SAS-SV > 31) and 40 without PSU were asked to keep sleep diary for 2 weeks and complete the WSPS again.

Results: EFA and CFA supported a six-item unidimensional structure of the WSPS. The WSPS demonstrated acceptable internal consistency among undergraduates. The WSPS showed good concurrent validity with other relevant variables including PSU, BP, sleep quality, and depression. Scalar invariance of the WSPS between undergraduates with/without PSU was supported, as well as scalar invariance across gender. The WSPS showed good convergent validity with self-report everyday while-in-bed smartphone use duration and good discriminant validity with sleep duration and sleep onset latency recorded by sleep diary. The WSPS also presented good test-retest reliability among undergraduates with/without PSU.

Conclusion: The WSPS is a reliable and valid measure of while-in-bed-smartphone-use-induced sleep procrastination in undergraduates with/without PSU.