Table 1.

Risk factors for MOH and associated odds ratios identified in three studies [Hagen et al. (4), Scher et al. (5), and He et al. (6)].

Risk factor	Odds ratio
Age (under 50 y.o)	1.8
Gender (Female)	1.9
Low educational level	1.9
Chronic musculoskeletal complaints	1.9
Gastrointestinal complaints	1.6
Anxiety or depression	4.7
Smoking status	1.8
Physical inactivity	2.7
Metabolic syndrome	5.3
High daily caffeine intake	1.4
Tranquilizers' use	5.2
Aspirin's use	0.5
Ibuprofen's use	0.7
Opioids' use	2.3