The Association between Stress and Sleep Quality in Physical Therapy Students
Purpose/Hypothesis:
Sleep is essential to performance, both physically and intellectually.1,2 Poor quality sleep has been linked to lower academic achievement.1 Insufficient sleep is frequently unrecognized,3 and can be confused with signs of depression.4 Students involved in a physical therapy graduate program must perform and are graded upon psychomotor skills and cognitive learning. Sleep enhances motor learning of complex functional motor skill tasks and adequate sleep should be considered essential for motor learning.2 Poor quality sleep correlates with poor academic performance in college age students.1 Stress from academics and life events can disrupt sleep patterns and result in a change in sleep behaviors. Students are more likely to report upon stress level than poor quality sleep to advisors, professors, faculty, or healthcare providers.3,5 A better understanding of how sleep quality and perceived levels of stress correlate can guide academic faculty and health care providers to advise students to develop methods of academic success.
High levels of perceived stress may be associated with impaired sleep in college students, but this relationship has not been fully examined. This study examined the association between self-perceived stress levels and sleep quality in college students enrolled in a graduate level physical therapy program utilizing the Perceived Stress Scale (PSS) and Pittsburgh Sleep Quality Index (PSQI).
Number of Subjects:
A sample of 81 male and female students currently enrolled first and second year Doctorate of Physical Therapy (DPT) students consented to completing the PSS and PSQI. Of the 79 respondents, 4 met exclusion criteria of age greater than 40 years or previous diagnosis of sleep pathology.
Materials and Methods:
Participants reported their age, gender, and year in DPT program and then completed the PSS and PSQI tools. The PSS was used to assess perceived stress in the previous month in different situations using a 0 - 4 Likert scale. The sum of all responses was used for analysis. Higher scores indicate greater perceived stress.
The PSQI was used to assess sleep quality over the previous month. The 19 items were grouped into seven component scores and these were summed to determine global PSQI score. The global score was utilized in analysis with higher scores indicating poorer sleep quality. Any global PSQI score greater than 5 is considered poor sleeper and identifies potential need for sleep intervention.
The primary analysis of this study was multiple linear OLS regression with standard selection to establish a relationship between PSS and PSQI, while controlling for age, gender, and year in program. Female gender (r=0.28, p=0.015) and PSS (r=0.65, p<.0001) had significant correlations. Once assumption testing was completed, linear regression models were fit. The Omnibus model fit was determined with the regression F test, alpha set to 0.05
Results:
Seventy-four participants’ data were analyzed. The mean age was 24 (SD 1.87) with a range from 21 to 34 years, and included 42 (56%) identifying as female gender and 33 (44%) identifying as male. The distribution between year in program was even at 36 (48%) within the first year and 39 (52%) within the second year of the program. Mean score for PSS was 17.11 (SD 7.03) and mean score for PSQI was 7.71 (SD 3.93). The multiple linear regression for the full model had a significant omnibus fit, F(42,73) = 26.32, p= <.0001, adjusted R2 = 0.40, indicating that the predictors, PSS and gender, accounted for 40% of the linear variance of PSQI. After controlling for the other predictors, for each number increase in PSS score, PSQI global score was increased by 1.41. Female gender has a greater impact on sleep quality in the presence of moderate or high levels of perceived stress than age or student's level (year) in program.
Conclusions:
This study found that as perceived stress level increased, sleep quality decreased in DPT students. This finding was affected by gender but not age nor year in program. Stress level in DPT education is predictive of poor sleep.
Clinical Relevance:
Impaired sleep quality is known to impact academic performance and health. It is important that educators consider the impact of stressful times in DPT curricula on the ability of students to have good quality sleep. Counseling students on sleep hygiene as well as stress management strategies may improve their health and perhaps academic performance. Future studies should examine the impact of sleep hygiene strategies on perceived stress levels and performance in DPT education.