The prevalence and awareness of sleep apnea in patients suffering chronic pain: an assessment using the STOP-Bang sleep apnea questionnaire

Figures & data

Table 1 Demographic characteristics of opioid users and non-users

Demographic characteristics	Opioid users n=196	Non-opioid users n=101	Total n=297
Age (years)
Mean ± SD (median, range)	56.6±14.0 (57, 19–90)	59.2±13.6 (60, 22–87) P=NS	57.5±13.9 (58, 19–90)
Gender
Total	193*	99*	292*
Female	133 (68.9%)	60 (60.6%)	193 (66.1%)
Male	60 (31.1%)	39 (39.4%)	99 (33.9%)
Not known	3 (1.6%)	2 (3.0%) P=NS	5 (1.7%)
Race
Total	188*	94*	282*
Caucasian	148 (78.7%)	81 (86.2%)	229 (81.2%)
African American	13 (6.9%)	2 (2.1%)	15 (5.3%)
Asian	5 (2.7%)	4 (4.3%)	9 (3.2%)
Hispanic	17 (9.0%)	4 (4.3%)	21 (7.5%)
Native Hawaiian or Pacific Islander	1 (0.5%)	0 (0.0%)	1 (0.4%)
American Indian or Alaskan Native	2 (1.1%)	0 (0.0%)	2 (0.7%)
Prefer not to answer	2 (1.1%)	3 (3.2%)	5 (1.8%)
Not known	8 (4.3%)	8 (8.5%) P=NS	15 (5.3%)
BMI
Total	192*	99*	291*
Underweight (BMI <18.5)	3 (1.6%)	2 (2.0%)	5 (1.7%)
Healthy weight (BMI ≥18.5 and <25)	48 (25.0%)	28 (28.3%)	76 (26.1%)
Overweight (BMI ≥25 and <30)	67 (34.9%)	33 (33.3%)	100 (34.4%)
Obese (BMI ≥30)	67 (38.5%)	36 (36.4%)	110 (37.8%)
Not known	4 (2.1%)	3 (3.0%) P=NS	6 (2.1%)
Diagnosed or treated for pain disorder of ≥6 months
Total	196	101	297
Yes	187 (95.4%)	87 (86.1%)	274 (91.9%)
No	9 (4.6%)	15 (14.9%) P=0.002	24 (8.1%)

Notes: Not all participants answered all questions. The number of respondents (*) in each section are shown. Missing answers are given as “not known” in the table. P, significance of difference between opioid and non-opioid users.

Abbreviation: NS, not significant.

Table 2 Patient awareness of sleep apnea risks

	Opioid users	Opioid non-users	Total
STOP-Bang (score ≥3)	n=196	n=101	n=297
Positive	116 (59.2%)	57 (56.4%)	173 (58.3%)
Negative	80 (40.8%)	44 (43.6%)	124 (41.7%)
Do you know what sleep apnea is?	n=191*	n=99*	n=290*
Yes	174 (91.1%)	89 (89.9%)	263 (90.7%)
No	17 (8.9%)	10 (10.0%)	27 (9.3%)
Have you or your health care provider ever discussed your risk of sleep apnea?	n=192*	n=98*	n=290*
Yes	72 (37.5%)	32 (32.6%)	104 (35.9%)
No	120 (62.5%)	66 (67.4%)	186 (64.1%)
Have you ever been tested for sleep apnea?	n=192*	n=98*	n=290*
Yes	59 (30.7%)	25 (25.8%)	84 (29.0%)
No	133 (69.3%)	73 (74.5%)	206 (71.0%)
Have you ever undergone a sleep study (polysomnogram)?	n=192*	n=99*	n=291*
Yes	62 (32.3%)	27 (27.3%)	89 (30.6%)
No	130 (67.7%)	72 (72.7%)	202 (69.4%)
Have you ever been diagnosed with sleep apnea?	n=192*	n=99*	n=291*
Yes	42 (21.9%)	24 (24.2%)	66 (22.7%)
No	150 (78.1%)	75 (75.8%)	225 (77.3%)
Have you ever been treated with positive airway pressure (CPAP or BiPAP)?	n=192*	n=97*	n=289*
Yes	42 (21.9%)	19 (19.6%)	61 (21.1%)
No	150 (78.1%)	78 (80.4%)	228 (78.9%)

Notes: None of the differences between groups were statistically significant by Chi-squared analysis. P-values ranged from 0.35 to 0.74. Not all participants answered all questions. The number of respondents (*) to each question is given.

Table 3 Summary of outcomes for Epworth and STOP-Bang screening questionnaires

Screening questionnaire	Opioid user group n=196	Opioid non-user group n=101	Total n=297
Epworth Sleepiness Scale score – median (range)	7 (0–22) n=192*	7 (0–23) n=99*	7 (0–23) n=291*
Epworth Scale score >10 (excessive daytime sleepiness)	50/192* (25.9%)	22/99* (22.2%)	72/291* (24.2%)
STOP-Bang score 0	3 (1.5%)	0 (0.0%)	3 (1.0%)
STOP-Bang score 1	24 (12.3%)	13 (12.9%)	37 (12.5%)
STOP-Bang score 2	53 (27.0%)	31 (30.7%)	84 (28.3%)
STOP-Bang score 3	49 (25.0%)	17 (16.8%)	66 (22.2%)
STOP-Bang score 4	29 (14.8%)	22 (21.8%)	51 (17.2%)
STOP-Bang score 5	19 (9.7%)	6 (5.9%)	25 (8.4%)
STOP-Bang score 6	14 (7.1%)	8 (7.9%)	22 (7.4%)
STOP-Bang score 7	4 (2.0%)	4 (4.0%)	8 (2.7%)
STOP-Bang score 8	1 (0.5%)	0 (0.0%)	1 (0.3%)

Notes: There were no statistically significant differences between the opioid user and non-user groups on the Epworth Sleepiness Scale (P=0.59) or for STOP-Bang positivity (P=0.84).

* Not all participants answered all questions.

Figure 1 Opiate drug distribution among subjects.