Chronic Widespread Pain and Fibromyalgia Syndrome: Life-Course Risk Markers in Young People

Table 2

Familial and genetic influences for chronic widespread pain and fibromyalgia.

Pain context	Type of study	Population or clinic	Number of participants	Multivariate analysis	Reference	Overall quality
CWP	Twin study	Population	44,897	No	Kato et al. [37]	+++
CWP	Twin study	Population	926	Yes	Burri et al. [38]	++++
CWP	Twin study	Population	8564	Yes	Vehof et al. [39]	+++
CWP	Twin study	Population	2256	Yes	Malkin et al. [40]	+++
CWP	Prospective population cohort	Population	6589	Yes	Zadro et al. [41]	++++
CWP	Review	N/A	N/A	N/A	Kerr and Burri [42]	N/A
FMS	Family study	Clinic	805	Yes	Arnold et al. [43]	++
FMS	Review	N/A	N/A	N/A	Park et al. [44]	N/A

Overall quality:  + , very low;  ++ , low;  +++ , moderate;  ++++ , high.