A total of 555 responses were collected; 472 surveys were completed without any missing data. Partial responses were incorporated into the data analysis. Only responses that were complete were utilized to calculate the total SQS score. Participant demographics are presented in Tables 1 and 2.
The beginning of the survey focused on the general demographic and health demographic questions presented in Tables 1 and 2. The survey then focused on questions related to sleep-related diagnoses, symptoms, medications, sleep hygiene and a variety of other sleep-related issues. First, the participants were asked if they had ever been formally diagnosed with a sleep disorder; they were permitted to check off as many responses as applied. Of the 548 who responded: 284 (51.8%) no sleep disorder; 156 (28.5%) sleep apnea; 113 (20.6%) insomnia; 12 (2.2%) narcolepsy; 68 (12.4%) restless leg syndrome; 8 (1.5%) sleep hypoventilation; 33 (6.0%) hypersomnia; 13 (2.4%) REM sleep behavior disorder; 7 (1.3%) circadian sleep rhythm disorder. Next, the participants were asked if they regularly (more than three times a week) experienced symptoms related to poor or disruptive sleep; they were permitted to check off multiple symptoms. Of the 548 who responded: 237 (43.2%) snoring; 227 (41.4%) bruxism; 89 (16.2%) sleep talking; 16 (2.9%) sleep walking; 93 (17.0%) nightmares; 29 (5.3%) night terrors; 192 (35.0%) vivid dreams; 97 (17.7%) none of the listed symptoms.
The survey then sought to quantify prescription and non-prescription medication usage. Participants reported taking a prescription medication with a known side effect of fatigue or drowsiness: 246 (45.4%) yes, 240 (44.3%) no, and 56 (10.3%) unsure. Participants reported taking an over-the-counter medication with a known side effect of fatigue or drowsiness: 134 (24.7%) yes, 378 (69.7%) no, and 30 (5.5%) unsure. Participants reported taking a prescription medication with a known side effect of insomnia or alertness: 68 (12.5%) yes, 398 (73.4%) no, and 76 (14.0%) unsure. Participants reported taking an over-the-counter medication with a known side effect of insomnia or alertness: 21 (3.9%) yes, 477 (88.0%) no, and 44 (8.1%) unsure. Participants were asked if they were taking any prescription medication specifically for the purpose of achieving a better quality of sleep: 167 (30.8%) yes, 373 (68.8%) no, and 2 (0.4%) unsure. Participants were asked if they were taking any over-the-counter medication specifically for the purpose of achieving a better quality of sleep: 166 (30.6%) yes, 373 (68.8%) no, and 3 (0.6%) unsure. Given caffeine can have an impact similar to many medications, participants were asked how many cups of caffeinated drinks (coffee, tea, soda) they typically drank in a day. Of the 532 who responded: 91 (17.1%) none; 140 (26.3%) one cup; 176 (33.1%) two cups; 100 (18.8%) three to five cups; 25 (4.7%) six or more cups. Participants were asked how many cups of caffeinated drinks (coffee, tea, soda) they drank within two hours of going to sleep. Of the 532 who responded: 464 (87.2%) none; 52 (9.8%) one cup; 15 (2.8%) two cups; 1 (0.2%) three to five cups; 0 (0%) six or more cups.
Sleep hygiene may have a significant impact on sleep quality. Participants were asked about their sleep hygiene practices; they were permitted to check off all that applied. Of the 548 who responded: 288 (52.6%) consistent sleep schedule; 233 (42.5%) relaxing bedtime/pre-bedtime routine; 368 (67.2%) dark and quiet bedroom; 431 (78.6%) cool/comfortable bedroom temperature; 169 (30.8%) electronics turned off in the bedroom; 56 (10.2%) avoid electronics one hour prior to bedtime; 335 (61.1%) avoid large meals and caffeine immediately prior to bedtime; 170 (31.0%) engage in regular physical activity; 211 (38.5%) avoid daytime naps; 22 (4.0%) no sleep hygiene practices used.
The survey also sought to quantify the amount of sleep and awake time. First, participants were asked how many hours of sleep they typically get each night, including time spent lying awake in bed. Of the 536 who responded: 20 (3.7%) less than four hours, 78 (14.6%) four to five hours, 255 (47.6%) six to seven hours, 183 (34.1%) eight or more hours. Next, the participants were asked how long they were typically awake if they woke up during the night. Of the 533 who responded: 108 (20.3%) less than 5 minutes, 141 (26.5%) 6-19 minutes, 121 (22.7%) 20-59 minutes, 109 (20.5%) 1-2 hours, 54 (10.1%) more than 2 hours. Participants were then asked how many times they would wake up during the night to urinate. Of the 536 respondents: 118 (22.0%) none, 219 (40.9%) once, 118 (22.0%) twice, 53 (9.9%) three times, 28 (5.2) four or more times. Next, the participants were asked how many daytime naps (lasting five minutes or longer) they took on an average working day. Of the 530 respondents: 368 (69.4%) none, 154 (29.1%) one or two, 6 (1.1%) three or four, 2 (0.4%) five or more. Participants were asked how many daytime naps (lasting five minutes or longer) they attempted to take but had trouble falling asleep; of the 530 respondents: 428 (80.8%) reported none, 94 (17.7%) one or two, 6 (1.1%) three or four, and 2 (0.4%) five or more.
The survey also explored the issues of pain, mental health, smoking and shift work, given that all of these could have a potential impact on sleep quality. First, the participants were asked about whether they experience chronic pain that interferes with their sleep. Of the 531 who responded: 310 (58.4%) yes, 204 (38.4%) no, 17 (3.2%) unsure. Next, the participants were asked about their mental health: 149 (28.1%) reported anxiety, 151 (28.5%) depression, 37 (7.0%) other mental health diagnosis, 193 (36.4%) no mental health diagnosis. Participants were then asked about their smoking history. Of the 529 who responded: 379 (71.6%) never smoked, 25 (4.7%) smoked for 1-2 years, 16 (3.0%) smoked for 3-5 years, 21 (4.0%) smoked for 6-10 years, 20 (3.8%) smoked for 11-15 years, 68 (12.9%) smoked for more than 15 years. Finally, the participants were asked about their work shifts. Of the 530 who responded: 321 (60.6%) are not currently working or are working but do not follow specific hours that would interfere with sleep; 13 (2.5%) work very early morning shifts, 173 (32.6%) work traditional day shifts, 10 (1.9%) work late afternoon/early evening shifts, 4 (0.8%) work night shifts, 9 (1.7%) work rotating shifts.
There were 472 participants who completed the SQS; the mean score was 43.0 (SD = 13.1) with a range from 5.0 to 81.0. After converting the SQS to mild, moderate, and severe categories (developed by John et al. in 2022 [15]), 67 (14.2%) had mild impairment, 339 (71.8%) had moderate impairment, and 66 (14.0%) had severe impairment.
A one sample t test was used to compare the results of the SQS for this sample of participants with normative data and with data collected from research done on populations with other diagnoses. In 2006, Yi et al. validated the SQS using individuals with a diagnosis of insomnia and a control group. [14] Yi et al. found the mean total SQS score for those with insomnia was 31.1 (SD = 13.61, n = 191) and for the control group the mean SQS was 15.8 (SD = 9.06, n = 332).[14] A one sample t test was used to compare the mean SQS score (43.0) from this sample of individuals with a IEI diagnosis to the two groups in the validation study. The mean SQS for individuals with IEI (43.0) was compared to the mean SQS for those with insomnia (31.1); there was a significant difference, t(471) = 19.773, p < 0.001. The mean SQS for individuals with IEI (43.0) was then compared to the mean SQS for the control group (15.8); again there was a significant difference, t(471) = 45.150, p < 0.001. In 2009, Yi et al. studied sleep quality in individuals with a diagnosis of obstructive sleep apnea syndrome (OSAS).[16] In this study, the OSAS group had a mean SQS score of 27.3 (SD = 10.95, n = 40) and the control group had a mean SQS of 9.7 (SD = 6.16, n = 37). The mean SQS for individuals with IEI (43.0) was compared to the mean SQS for those with OSAS (27.3); there was a significant difference, t(471) = 26.076, p < 0.001. The mean SQS for individuals with IEI (43.0) was then compared to the mean SQS for the control group (9.7); again there was a significant difference, t(471) = 55.268, p < 0.001.
More recently, a 2022 study by Çakan and Öztürk examined sleep quality in patients with a diagnosis of allergic rhinitis using the SQS.[17] In this study, the allergic rhinitis group had a mean SQS score of 68.68 (SD = 13.15, n = 65) and the control group had a mean SQS of 47.72 (SD = 9.3, n = 65). The mean SQS for individuals with IEI (43.0) was compared to the mean SQS for those with allergic rhinitis (68.68); there was a significant difference, t(471) = -42.559, p < 0.001. The mean SQS for individuals with IEI (43.0) was then compared to the mean SQS for the control group (47.72); again there was a significant difference, t(471) = -7.794, p < 0.001. In another recent study, John et al. [15] examined sleep quality in patients who had been diagnosed with Covid-19. In this study, the participants had a mean SQS score of 28.89 (SD = 12.22, n = 782). The mean SQS for individuals with IEI (43.0) was compared to the mean SQS for those with Covid-19 (28.89); there was a significant difference, t(471) = 23.439, p < 0.001.
A Chi Square Test of Independence was used to determine if there was any association between demographic or lifestyle factors that were included in the survey and sleep quality (using the SQS ranked as mild, moderate, or severe). Results are provided in Table 3.