title: Work-related activities that may contribute to musculoskeletal symptoms among dental students: validation study.
abstract: Dentists are exposed to occupational hazards, such as musculoskeletal disorders, in which symptoms can manifest early in clinical practice.
  
  
  
  To estimate the reliability and validity of the Portuguese version of the "Questionnaire on work-related activities that may contribute to musculoskeletal symptoms" when applied to dental students.
  
  
  
  553 Brazilian students participated in the study. The one-factor structure originally proposed was tested through confirmatory factor analysis (CFA) using the indexes c2/df, CFI, GFI, and RMSEA. After observing an inadequate good fit (c2/df=7.140, CFI=0.791, GFI=0.778, RMSEA=0.129), the sample was subdivided into 3 groups and an exploratory factor analysis was conducted (EFA) (n=255). A CFA was then conducted using a subsample (n=113). To test the invariance of the obtained factorial solution, a multi-group analysis was performed using a third sample, independent from the others (n=185). The convergent (AVE) and discriminant (r2) validity were assessed. The composite reliability (CR), Cronbach's alpha coefficient (a), and intra-class correlation coefficient (r) were calculated.
  
  
  
  In the EFA, 3 factors were extracted: "Repetitiveness," "Working posture," and "External factors" (c2=21895.154; p<0.001; KMO=0.905; l1=6.683; l2=1.464; l3=1.277) that explained 62.82% of the total variance. The three-factor model presented an adequate good fit (n=113 and n=185) (c2/df=2.259; CFI=0.885; GFI=0.833; RMSEA=0.066). The convergent validity was compromised only for "Repetitiveness" (AVE=0.412-0.653). The discriminant validity (r2=0.333-0.428), composite reliability, internal consistency, and reproducibility were adequate for all factors (CR=0.736-0.883; a=0.747-0.876; r=0.729-0.940).
  
  
  
  The questionnaire proved to be reliable and valid for the sample of dentistry students if the three-factor model is used.
authors.affiliation: Araraquara Dental School - UNESP, Univ Estadual Paulista. psgarcia@foar.unesp.br.
authors.forename: Patrícia Petromilli Nordi Sasso
authors.initials: PP
authors.lastname: Garcia
authors.forename: Cristina Dupim
authors.initials: CD
authors.lastname: Presoto
authors.forename: João
authors.initials: J
authors.lastname: Maroco
authors.forename: Juliana Alvares Duarte Bonini
authors.initials: JA
authors.lastname: Campos
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D009140:Musculoskeletal Diseases / Q000209:etiology*; D009784:Occupational Diseases / Q000209:etiology*; D057566:Self Report; D013335:Students, Dental; D055815:Young Adult
keywords: Validity of tests; musculoskeletal diseases; perception; psychometrics