High Perceived Stress and Low Self-Efficacy are Associated with Functional Somatic Disorders: The DanFunD Study

Figures & data

Table 1 Characteristics of the Study Participants

	Female	Age	Social Status	Perceived Stress	Self-Efficacy	Neuroticism	ALE
	N (%)	Median (IQR)	Median (IQR)	Median (IQR)	Median (IQR)	Median (IQR)	Median (IQR)
Total questionnaire sample (n = 9656)	5203 (53.9)	54 (44–64)	7 (6–8)	10 (6–14)	21 (18–25)	16 (11–21)	5 (3–8)
FSD overall (n = 1543)	1041 (67.5)	55 (46–63)	6 (5–7)	14 (9–19)	19 (15–24)	20 (15–26)	6 (4–9)
Single-organ FSD (n = 1447)	967 (66.8)	55 (47–63)	6 (5–7)	14 (9–19)	20 (16–24)	20 (15–26)	6 (4–6)
Cardiopulmonary (n = 81)	52 (64.2)	57 (46–62)	7 (5–7)	16 (11–21)	20 (17–24.5)	21 (15–28)	7 (4–11)
Gastrointestinal (n = 331)	218 (65.9)	51 (39–62)	6 (5–7)	14 (9–19)	20 (16–25)	21 (15–27)	6 (3–9)
Musculoskeletal (n = 969)	641 (66.2)	57 (50–65)	6 (5–7)	13 (9–17)	20 (16–24)	19 (14–24)	6 (4–9)
General symptom/fatigue (n = 323)	247 (76.5)	48 (38–56)	6 (5–7)	19 (14–24)	18 (14–23)	25 (19–31)	6 (3–6)
Multi-organ FSD (n = 96)	75 (77.1)	51 (42–58)	6 (5–7)	20 (15–24)	16 (12–22)	26.5 (22–32)	8 (4–11)
Irritable bowel (n = 337)	252 (74.8)	50 (40–60)	6 (5–7)	14 (10–19)	19 (15–25)	22 (16–27)	5 (3–8)
Chronic widespread pain (n = 442)	342 (77.4)	58 (50–65)	6 (5–7)	14 (9–19)	19 (15–25)	20 (15–26)	7 (3–10)
Chronic fatigue (n = 823)	576 (70.0)	50 (40–59)	6 (5–7)	17 (12–22)	19 (15–24)	24 (18–29)	6 (4–9)
Total interviewed sample (n = 1590)	942 (59.3)	54 (44–63)	7 (5–8)	12 (7–17)	21 (17–25)	18 (13–25)	6 (4–8)
FSD overall (n = 412)	299 (72.3)	51 (42–59)	6 (5–7)	17 (11–22)	19 (15–24)	23.5 (17–29)	6 (4–10)
Single-organ FSD (n = 326)	228 (69.9)	51 (42–60)	6 (4–7)	16 (10–21)	19 (15–25)	23 (16–28)	6 (4–9)
Cardiopulmonary (n = 47)	32 (68.1)	51 (37–59)	7 (6–7)	18 (15–22)	19 (15–25)	24 (19–30)	6 (4–11)
Gastrointestinal (n = 166)	115 (69.3)	53 (41–61)	6 (5–7)	15 (10–20)	20 (16–26)	23 (17–28)	6 (4–9)
Musculoskeletal (n = 107)	79 (73.8)	53 (47–60)	6 (5–7)	16 (11–20)	20 (15–25)	21 (15–26)	6 (4–9)
General symptom/fatigue (n = 111)	80 (72.1)	49 (40–56)	6 (5–7)	19 (14–23)	18 (14–21)	26 (20–31)	7 (4–11)
Multi-organ FSD (n = 86)	71 (82.6)	48.5 (39–57)	6 (5–7)	20 (14–23)	18 (13–23)	26 (18–32)	6.5 (3–10)

Abbreviations: ALE, Adverse life events; IQR, interquartile range; FSD, functional somatic disorder.

Table 2 Association Between Questionnaire-Defined Functional Somatic Disorders and Functional Somatic Syndromes, Perceived Stress and Self-Efficacy

	Self-Perceived Stress		Self-Efficacy
	Model 1	Model 2	Model 1	Model 2
	PR (95% CI)	PR (95% CI)	PR (95% CI)	PR (95% CI)
FSD overall (n = 1219)	1.09 (1.08–1.09)	1.06 (1.05–1.07)	0.97 (0.96–0.98)	1.01 (1.00–1.02)
Single-organ FSD (n = 1117)	1.08 (1.06–1.09)	1.06 (1.05–1.07)	0.97 (0.96–0.98)	1.01 (1.00–1.03)
Cardiopulmonary subtype (n = 69)	1.15 (1.12–1.19)	1.12 (1.08–1.17)	1.00 (0.96–1.04)	1.07 (1.03–1.12)
Gastrointestinal subtype (n = 271)	1.11 (1.09–1.13)	1.06 (1.04–1.08)	0.97 (0.95–0.99)	1.03 (1.01–1.05)
Musculoskeletal subtype (n = 716)	1.08 (1.07–1.09)	1.06 (1.05–1.08)	0.98 (0.97–0.99)	1.01 (0.99–1.02)
General symptom/fatigues subtype (n = 261)	1.18 (1.16–1.19)	1.13 (1.11–1.16)	0.93 (0.91–0.95)	1.01 (0.99–1.03)
Multi-organ FSD (n = 76)	1.20 (1.16–1.24)	–	0.97 (0.96–0.98)	–
Irritable bowel (n = 256)	1.11 (1.09–1.13)	1.06 (1.04–1.08)	0.95 (0.94–0.97)	1.01 (0.99–1.03)
Chronic widespread pain (n = 325)	1.11 (1.09–1.12)	1.09 (1.07–1.11)	0.98 (0.96–0.99)	1.02 (1.00–1.04)
Chronic fatigue (n = 658)	1.13 (1.12–1.14)	1.10 (1.08–1.11)	0.95 (0.94–0.96)	1.01 (1.00–1.02)

Notes: Model 1: Adjusted for sex, age, and social status. Model 2: Adjusted for sex, age, social status, and neuroticism. “–”: Could not be estimated because of low number of cases.

Abbreviations: PR, prevalence ratio; CI, confidence interval; FSD, functional somatic disorders.

Table 3 Association Between Clinical Interview-Established Functional Somatic Disorders, Perceived Stress and Self-Efficacy

	Self-Perceived Stress		Self-Efficacy
	Model 1	Model 2	Model 1	Model 2
	PR (95% CI)	PR (95% CI)	PR (95% CI)	PR (95% CI)
FSD overall (n = 392)	1.06 (1.05–1.07)	1.04 (1.03–1.06)	0.98 (0.96–0.99)	1.01 (0.99–1.03)
Single-organ FSD (n = 303)	1.05 (1.04–1.07)	1.04 (1.02–1.06)	0.98 (0.96–0.99)	1.01 (0.99–1.03)
Cardiopulmonary subtype (n = 47)	1.13 (1.09–1.16)	-	0.94 (0.89–0.99)	-
Gastrointestinal subtype (n = 157)	1.06 (1.04–1.08)	1.03 (1.00–1.06)	0.98 (0.96–1.01)	1.03 (1.00–1.06)
Musculoskeletal subtype (n = 104)	1.07 (1.04–1.09)	1.07 (1.03–1.11)	0.98 (0.95–1.02)	-
General symptoms subtype (n = 106)	1.10 (1.08–1.12)	-	0.93 (0.90–0.96)	-
Multi-organ FSD (n = 82)	1.09 (1.06–1.12)	1.07 (1.02–1.11)	0.95 (0.92–0.99)	1.01 (0.97–1.05)

Notes: Model 1: Adjusted for sex, age, and social status. Model 2: Adjusted for sex, age, social status, and neuroticism. “–”: Could not be estimated because of low number of cases.

Abbreviations: PR, prevalence ratio; CI, confidence interval; FSD, functional somatic disorders.

Figure 1 Difference in self-perceived stress and self-efficacy between FSD and other disease groups.

Abbreviations: FSD, functional somatic disorder, operationalized as Bodily Distress Syndrome; PhyDis, physical disease only; FSD+PhyDis, functional somatic disorder and physical disease; Ref., reference; Solid lines, questionnaire-defined cases; Dashed lines, interview-established cases.