title: A multi-level decomposition of variance in somatic symptom reporting in families with adolescent children.
abstract: OBJECTIVE
  This paper examines four different levels of possible variation in symptom reporting: occasion, day, person and family.
  
  
  METHODS
  In order to rule out effects of retrospection, concurrent symptom reporting was assessed prospectively using a computer-assisted self-report method.
  
  
  METHODS
  A decomposition of variance in symptom reporting was conducted using diary data from families with adolescent children. We used palmtop computers to assess concurrent somatic complaints from parents and children six times a day for seven consecutive days. In two separate studies, 314 and 254 participants from 96 and 77 families, respectively, participated. A generalized multilevel linear models approach was used to analyze the data. Symptom reports were modelled using a logistic response function, and random effects were allowed at the family, person and day level, with extra-binomial variation allowed for on the occasion level.
  
  
  RESULTS
  Substantial variability was observed at the person, day and occasion level but not at the family level.
  
  
  CONCLUSIONS
  To explain symptom reporting in normally healthy individuals, situational as well as person characteristics should be taken into account. Family characteristics, however, would not help to clarify symptom reporting in all family members.
authors.affiliation: Department of Social and Preventive Medicine, University of Bern, Switzerland. michel@ispm.unibe.ch
authors.forename: Gisela
authors.initials: G
authors.lastname: Michel
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D003936:Diagnosis, Computer-Assisted; D005191:Family Characteristics; D005260:Female; D006801:Humans; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D019370:Observation; D011336:Probability; D012650:Self Disclosure; D013001:Somatoform Disorders / Q000175:diagnosis / Q000503:physiopathology*; D013557:Switzerland