title: Fatigue and patterns of pain in fibromyalgia: correlations with anxiety, depression and co-morbidity in a female county sample.
abstract: This study explored the prevalence of fibromyalgia, the relationship of anxiety and depression with two major symptoms (pain and fatigue), and the role of co-morbidity. Participants were recruited from the Nord-Trøndelag Health Study (The HUNT Study) in Norway (N = 92,936). They were females given the diagnosis of fibromyalgia by their doctor (N = 1,816), divided into one sample without (N = 977) and another with (N = 839) co-morbidity. Owing to colinearity between anxiety and depression, extreme groups were defined according to high vs. low anxiety and depression scores. About four-fifths of the initial sample were excluded by this approach, which permitted a two x two factorial split-plot ANCOVA for the assessment of the relations of anxiety and depression with pain and fatigue. The overall prevalence was 3.2%, which obscured a highly biased sex difference with 5.2% for females and .9% for males. Results from the sample without co-morbidity (N = 977) supported the idea of independent partial correlations of anxiety and depression with pain and fatigue. A different trend was indicated in the co-morbidity sample (N = 839) where fatigue was only significantly associated with depression, whereas pain was associated with anxiety. The idea of widespread pain was supported consistently only in participants without co-morbidity who scored low on anxiety. Age, incident pain and depression contributed to a discriminant function reflecting the status of co-morbidity.
authors.affiliation: HUNT Research Centre, Verdal, Norway. nanna.kurtze@medisin.ntnu.no
authors.forename: N
authors.initials: N
authors.lastname: Kurtze
authors.forename: S
authors.initials: S
authors.lastname: Svebak
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001007:Anxiety / Q000523:psychology*; D003863:Depression / Q000523:psychology*; D005221:Fatigue / Q000523:psychology*; D005260:Female; D005356:Fibromyalgia / Q000453:epidemiology / Q000523:psychology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D010146:Pain / Q000523:psychology*; D010147:Pain Measurement; D011594:Psychometrics; D013997:Time Factors