Posttraumatic stress disorder and sleep quality among urban firefighters in Thailand

Figures & data

Table 1 Prevalence of PTSD and general information among firefighters

General information		PTSD (N =1215)				p-value
		Yes (n =78; 6.4%)		No (n =1137; 93.6%)
		n	%	n	%
Age (median (IQR); years)		39.5 (35.8–43.3)		39.0 (36.0–44.0)		0.653^b
Education level						0.021^a*
	Secondary/Vocational-High Certificate	40	51.3	433	38.1
	Bachelor’s Degree or higher	38	48.7	704	61.9
Marital status						0.590^a
	Single/Widow	30	38.5	403	35.4
	Married/Living Together	48	61.5	734	64.6
Regular exercise, n (%)						0.053^a
	Yes	54	69.2	894	78.6
	No	24	30.8	243	21.4
Body mass index (kg/m^2), mean (SD)		24.06 (3.30)		23.83 (3.56)		0.554^c
Alcohol consumption, n (%)						0.682^a
	Yes	60	76.9	851	74.8
	No	18	23.1	286	25.2
Smoker, n (%)						0.003^a*
	Yes	34	43.6	314	27.6
	No	44	56.4	823	72.4
Duration of work (years), median (IQR)		13.00 (8.75–13.00)		10.00 (8.00–13.00)		0.001^b*
Exposure to major fire in Thailand, n (%)						0.024^a*
	Yes	63	80.8	780	68.6
	No	15	19.2	357	31.4
Occupational injury, n (%)						0.409^a
	Yes	34	43.6	442	38.9
	No	44	56.4	695	61.1
Depression (PHQ-9) (median (IQR))		9.00 (7.00–13.00)		2.00 (0.00–5.00)		<0.001^b*

Notes: *Significant at a p-value <0.05. ^aChi-square, ^bMann-Whitney U test, ^cIndependent t-test.

Abbreviations: IQR, interquartile range; PHQ, Patient Health Questionnaire.

Table 2 The comparison of Pittsburgh Sleep Quality index between the firefighters with and without PTSD

Sleep quality components	PTSD (N =1215)				p-value
	Yes (n =78; 6.4%)		No (n =1137; 93.6%)
	n	%	n	%
Subjective sleep quality					0.001*
Very good	16	20.5	323	28.4
Fairly good	39	50.0	649	57.1
Fairly bad	18	23.1	146	12.8
Very bad	5	6.4	19	1.7
Sleep latency (mins)					<0.001*
$\le$15	3	3.8	393	34.6
16–30	16	20.5	232	20.4
31–60	58	74.4	503	44.2
$>$60	1	1.3	9	0.8
Sleep duration (hrs)					0.003*
$\le$ 5.0	37	47.4	355	31.2
5.1–6.0	26	33.3	338	29.7
6.1–7.0	7	9.0	251	22.1
$>$ 7.0	8	10.3	193	17.0
Sleep efficiency					<0.001*
$<$ 65%	25	32.1	190	16.7
65–74%	18	23.1	155	13.6
75–85%	24	30.8	291	25.6
$>$ 85%	11	14.1	501	44.1
Sleep disturbances					<0.001*
Not during the past month	1	1.3	80	7.0
Less than once a week	25	32.1	764	67.2
Once or twice a week	48	61.5	285	25.1
Three or more times a week	4	5.1	8	0.7
Use of sleep medication					<0.001*
Never	48	61.5	1,059	93.1
Ever	30	38.5	78	6.9
Daytime dysfunction due to sleep					<0.001*
Never	9	11.5	407	35.8
$\le$2 times a week	67	85.9	726	63.9
$>$ 2 times a week	2	2.6	4	0.4
Overall sleep quality (Global PSQI Scores)					<0.001*
Good Sleep (PSQI $\le$ 5)	9	11.5	610	53.6
Poor sleep (PSQI $>$ 5)	69	88.5	527	46.4

Note: *Significant at a p-value <0.05 for Chi-square Test.

Abbreviations: PSQI, Pittsburgh Sleep Quality Index, PTSD, posttraumatic stress disorder.

Table 3 Multivariate analysis of posttraumatic stress disorder and sleep quality

Sleep quality PTSD	Poor subjective sleep quality		Long sleep latency		Short sleep duration		Poor sleep efficiency
	OR (95% CI)	AOR (95% CI)*	OR (95% CI)	AOR (95% CI)*	OR (95% CI)	AOR (95% CI)*	OR (95% CI)	AOR (95% CI)*
No	1.00 (Ref)	1.00 (Ref)	1.00 (Ref)	1.00 (Ref)	1.00 (Ref)	1.00 (Ref)	1.00 (Ref)	1.00 (Ref)
Yes	1.54 (0.87–2.70)	2.12 (0.76–5.90)	3.79 (2.23–6.44)	2.99 (1.12–7.96)	1.79 (0.85–3.78)	2.59 (0.72–9.35)	4.80 (2.51–9.18)	7.74 (2.81–21.3)
Sleep quality PTSD	Sleep disturbances		Use of sleep medication		Day dysfunction due to sleep		Poor sleep quality (Overall)
	OR (95% CI)	AOR (95% CI)*	OR (95% CI)	AOR (95% CI)*	OR (95% CI)	OR (95% CI)	AOR (95% CI)*	OR (95% CI)
No	1.00 (Ref)	1.00 (Ref)	1.00 (Ref)	1.00 (Ref)	No	1.00 (Ref)	1.00 (Ref)	1.00 (Ref)
Yes	5.83 (0.80–42.45)	14.9 (1.23–182)	8.49 (5.09–14.14)	0.33 (0,07–1.53)	Yes	5.83 (0.80–42.45)	14.9 (1.23–182)	8.49 (5.09–14.14)

Note: *Multivariable adjusted for age, smoke, alcohol consumption, caffeine, duration of work, PHQ-9 score.

Abbreviations: PTSD, posttraumatic stress disorder, AOR, adjusted odds ratio; CI, confidence interval; OR, odds ratio.