title: Development of a survey to assess backpack use and neck and back pain in seventh and eighth graders.
abstract: OBJECTIVE
  The purpose of this study was to develop and test the reliability and validity of a pilot survey of backpack use and neck and back pain in seventh and eighth graders.
  
  
  METHODS
  A survey was developed on the basis of literature review and expert input. The survey was administered to 69 seventh and eighth graders. One week later, the survey was readministered to 20 students. Internal consistency was assessed with Cronbach's alpha coefficient. Test-retest reliability was examined by calculating the percentage of agreement and kappa values. Construct validity was assessed by determining whether hypothesized age and gender differences in responses were present.
  
  
  RESULTS
  The internal consistency of responses related to neck or back pain and backpack use was high, with Cronbach's alpha coefficients of 0.83 and 0.85, respectively. Percentage of agreement for the neck and back pain responses ranged from 45% to 100% (mean [SD] = 77% [15%]). The kappa coefficients ranged from 0.10 to 1.00 (mean [SD] = 0.54 [0.23]). Percentage of agreement for backpack use questions ranged from 60% to 100% (mean [SD] = 84% [9%]). The kappa coefficients ranged from 0.14 to 1.00 (mean [SD] = 0.59 [0.20]). Construct validity of the survey was partially supported. Age and gender differences in neck and back pain varied with the question. Age and gender differences in backpack use were consistent and as hypothesized.
  
  
  CONCLUSIONS
  Our findings provide preliminary support for the use of this survey with seventh and eighth graders. Additional testing is needed to assess reliability and validity in a larger, more diverse sample.
authors.affiliation: Dunn Physical Therapy (T.B.M.), Durham, NC, Division of Physical Therapy (D.E.T., J.K.F.), University of North Carolina at Chapel Hill, and Cecil G. Shep Center for Health Services Research (J.K.F.), Chapel Hill, NC.
authors.forename: Trupti B
authors.initials: TB
authors.lastname: Mehta
authors.forename: Deborah E
authors.initials: DE
authors.lastname: Thorpe
authors.forename: Janet K
authors.initials: JK
authors.lastname: Freburger