Appendix 1

Draft 38-item SFIS Questionnaire

The purpose of the first set of questions is to find out how your sleep has affected your daily life and how you felt over the past 7 days.

Please read each question carefully, choosing the response that best applies to your situation, without help from anyone. Please answer each question by selecting the one answer most appropriate for you.

1. Considering how you slept over the past 7 days, how often did you feel… / None of the time / A little of the time / Some of the time / Most of the time / All of the time
a. Tired during the day? / 11 / 12 / 13 / 14 / 15
b. Exhausted during the day? / 11 / 12 / 13 / 14 / 15
c. Sleepy during the day? / 11 / 12 / 13 / 14 / 15
d. Like you had less energy during the day? / 11 / 12 / 13 / 14 / 15
2. Considering how you slept over the past 7 days, how difficult was it for you to motivate yourself to… / Not at all / Slightly / Moderately / Quite a bit / Extremely
a. Do your usual daily activities? / 11 / 12 / 13 / 14 / 15
b. Care for yourself (e.g., bathing, dressing, shaving)? / 11 / 12 / 13 / 14 / 15
3. Considering how you slept over the past 7 days, how difficult has it been for you to… / Not at all / Slightly / Moderately / Quite a bit / Extremely
a. Focus on what you were doing? / 11 / 12 / 13 / 14 / 15
b. Stay alert? / 11 / 12 / 13 / 14 / 15
c. Remember things? / 11 / 12 / 13 / 14 / 15
d. Make decisions? / 11 / 12 / 13 / 14 / 15
4. Considering how you slept over the past 7 days, how good was the work you did (work refers to school work, paid work, volunteer work, or unpaid work around the house)? / Much worse than usual / A little worse than usual / About the same as usual / A little better than usual / Much better than usual
11 / 12 / 13 / 14 / 15
5. Considering how you slept over the past 7 days, how often did you… / None of the time / A little of the time / Some of the time / Most of the time / All of the time /
a. Put off doing things you needed to do? / 11 / 12 / 13 / 14 / 15
b. Take longer to finish things you needed to do? / 11 / 12 / 13 / 14 / 15
c. Have to force yourself to start things you needed to do? / 11 / 12 / 13 / 14 / 15
d. Have to force yourself to finish things you needed to do? / 11 / 12 / 13 / 14 / 15
e. Do just enough work to get by? / 11 / 12 / 13 / 14 / 15
f. Take time off from school or work (including work you do around the house)? / 11 / 12 / 13 / 14 / 15
g. Miss appointments? / 11 / 12 / 13 / 14 / 15
h. Get to school or work late (work includes work you do around the house and work you do for pay)? / 11 / 12 / 13 / 14 / 15
i. Doze off while working (e.g., household tasks, paid or non-paid work, school work)? / 11 / 12 / 13 / 14 / 15
j. Forgot what you were doing while working (work includes paid or nonpaid work, school work)? / 11 / 12 / 13 / 14 / 15
k. Make mistakes while doing something you had to do? / 11 / 12 / 13 / 14 / 15
6. Considering how you slept over the past 7 days, how much have the following been negatively affected? / Not at all / A little / Moderately / A lot / Extremely
a. Your enjoyment in social activities / 11 / 12 / 13 / 14 / 15
b. Your relationships (e.g., friends, family, partner) / 11 / 12 / 13 / 14 / 15
c. Your interest in being intimate with a partner / 11 / 12 / 13 / 14 / 15
7. Considering how you slept over the past 7 days, how often have you… / None of the time / A little of the time / Some of the time / Most of the time / All of the time
a. Turned down or cancelled plans to do something that you usually enjoy doing? / 11 / 12 / 13 / 14 / 15
b. Wanted to be left alone? / 11 / 12 / 13 / 14 / 15
8. Considering how you slept over the past 7 days, how often have you felt… / None of the time / A little of the time / Some of the time / Most of the time / All of the time
a. Irritable? / 11 / 12 / 13 / 14 / 15
b. Frustrated? / 11 / 12 / 13 / 14 / 15
c. Down? / 11 / 12 / 13 / 14 / 15
d. Anxious? / 11 / 12 / 13 / 14 / 15
e. Stressed? / 11 / 12 / 13 / 14 / 15
f. Overwhelmed / 11 / 12 / 13 / 14 / 15
9. Considering how you slept over the past 7 days, how frustrated were you by… / Not at all / A little / Moderately / A lot / Extremely
a. Your lack of energy? / 11 / 12 / 13 / 14 / 15
b. How many mistakes you made? / 11 / 12 / 13 / 14 / 15
c. Things you would usually ignore? / 11 / 12 / 13 / 14 / 15
10. Considering how you slept over the past 7 days, how bothered have you been that… / Not at all / A little / Moderately / A lot / Extremely
a. You got less done than you planned? / 11 / 12 / 13 / 14 / 15
b. You had trouble focusing on what you were doing? / 11 / 12 / 13 / 14 / 15

Appendix 2

Table A-1. Descriptive Statistics for 26-item SFIS and Validating Instruments

Instrument / Overall
N / Overall
Mean (SD) / Insomnia
N / Insomnia
Mean(std) / Control
N / Control
Mean(SD) / Effect Size /
SFIS (26 item version) / 432 / 53.5 (20.3) / 171 / 70.6 (16.4) / 261 / 42.3 (13.8) / 2.05
ESS Total Composite / 432 / 7.4 (4.6) / 171 / 9.0 (5.1) / 261 / 6.4 (3.9) / 0.66
FOSQ: Activity / 432 / 16.1 (3.3) / 171 / 14.1 (3.1) / 261 / 17.5 (2.7) / –1.28
FOSQ: Vigilance / 432 / 15.5 (3.7) / 171 / 13.9 (3.6) / 261 / 16.6 (3.4) / –0.79
FOSQ: Intimacy / 426 / 14.2 (6.6) / 169 / 11.7 (6.1) / 257 / 15.9 (6.5) / –0.65
FOSQ: Productive / 432 / 17.1 (3.0) / 171 / 15.9 (2.7) / 261 / 17.9 (3.0) / –0.69
FOSQ: Social / 432 / 17.9 (3.7) / 171 / 17.0 (3.9) / 261 / 18.4 (3.5) / –0.41
FOSQ: Composite / 432 / 80.7 (15.6) / 171 / 72.4 (14.0) / 261 / 86.1 (14.1) / –0.97
ISI Total / 432 / 8.5 (7.6) / 171 / 16.5 (4.5) / 261 / 3.2 (3.3) / 4.01
MOS: Sleep Disturbance Scale / 432 / 33.5 (29.0) / 171 / 62.4 (20.2) / 261 / 14.6 (14.8) / 3.23
MOS: Snoring Scale / 425 / 27.8 (28.2) / 168 / 33.0 (27.7) / 257 / 24.4 (28.1) / 0.31
MOS: Short of Breath Scale / 432 / 14.2 (26.1) / 171 / 20.6 (26.3) / 261 / 10.0 (25.0) / 0.42
MOS: Sleep Adequacy / 432 / 41.8 (27.4) / 171 / 25.5 (19.1) / 261 / 52.5 (26.8) / –1.00
MOS: Somnolence Scale / 432 / 28.0 (20.3) / 171 / 38.6 (19.4) / 261 / 21.0 (17.8) / 0.99
MOS: Sleep Problems Index I / 432 / 37.2 (20.2) / 171 / 56.5 (12.1) / 261 / 24.5 (13.3) / 2.40
MOS: Sleep Problems Index II / 432 / 36.2 (20.6) / 171 / 56.5 (12.7) / 261 / 22.9 (12.3) / 2.73
MOS: Sleep Quantity (Raw Score) / 431 / 6.4 (1.3) / 170 / 5.5 (1.2) / 261 / 7.0 (1.1) / –1.35
MOS: Optimal Sleep Scale / 431 / 0.4 (0.5) / 170 / 0.1 (0.3) / 261 / 0.6 (0.5) / –1.06
WPAI-GH: Pct work time missed due to health / 272 / 2.9 (11.8) / 108 / 6.0 (17.7) / 164 / 0.8 (3.7) / 1.40
WPAI-GH: Pct overall work impairment due to health / 272 / 15.0 (22.8) / 108 / 28.9 (25.9) / 164 / 5.9 (14.7) / 1.56
WPAI-GH: Pct impaired while working due to health / 277 / 14.0 (21.0) / 108 / 26.5 (23.5) / 169 / 6.0 (14.5) / 1.41
WPAI-GH: Pct other activities impaired due to health / 276 / 20.0 (24.9) / 107 / 37.1 (25.2) / 169 / 9.1 (17.6) / 1.59
PSQI: Subjective Sleep Quality / 432 / 1.3 (0.9) / 171 / 2.1 (0.6) / 261 / 0.7 (0.6) / 2.48
PSQI: Sleep Latency / 432 / 1.3 (1.2) / 171 / 2.3 (0.9) / 261 / 0.6 (0.7) / 2.46
PSQI: Sleep Duration / 431 / 1.5 (0.9) / 171 / 2.0 (0.6) / 260 / 1.1 (0.8) / 1.22
PSQI: Sleep Efficiency / 431 / 0.9 (1.2) / 171 / 1.8 (1.2) / 260 / 0.3 (0.7) / 2.23
PSQI: Sleep Disturbance / 432 / 1.4 (0.7) / 171 / 2.0 (0.6) / 261 / 1.0 (0.5) / 2.03
PSQI: Sleep Medication Usage / 432 / 0.9 (1.2) / 171 / 2.0 (1.2) / 261 / 0.1 (0.4) / 4.25
PSQI: Sleep Dysfunction / 432 / 1.0 (0.7) / 171 / 1.5 (0.6) / 261 / 0.6 (0.6) / 1.35
PSQI: Overall Composite / 432 / 8.1 (5.2) / 171 / 13.7 (2.9) / 261 / 4.4 (2.4) / 3.94

N Number, SD Standard Deviation, SFIS Sleep Functional Impact Scale, ESS Epworth Sleepiness Scale, FOSQ Functional Outcomes of Sleep Questionnaire, ISI Insomnia Severity Index, MOS Medical Outcomes Study, WPAI–GH Work Productivity and Activity Impairment–General Health Questionnaire, PSQI Pittsburgh Sleep Quality Index