title: Diary days needed to estimate activity among older African-American and Hispanic women.
abstract: OBJECTIVE
  The purpose of this study was to estimate variation in energy expenditure among older African-American and Hispanic female workers and nonworkers, and identify the number of days of diary self-report necessary to reliably estimate activity.
  
  
  METHODS
  227 women (111 African-American, 116 Hispanic) from the Women On The Move study completed a 7-d diary and were used in the analysis for this study (mean age 49.3 yr, SD = 7.0; mean weight 77.0 kg, SD = 17.6 kg; mean BMI 30, SD = 6.5). Kcal per day for total activity and specific types of activity were calculated for each subject and used in generalizability analyses.
  
  
  RESULTS
  Results indicated that 11 d of activity are needed to reliably estimate total activity for African-American nonworkers and 8 d for Hispanic nonworkers. For workers, 12 d of activity are needed to reliably estimate total activity for African-Americans and 14 d are required for Hispanics. Days of diary self-report required by activity type for African-Americans range from 6 to 48 for nonworkers and from 6 to 30 for workers. For Hispanics, days of diary self-report required by activity type range from 8 to 111 for nonworkers and 7 to 42 for workers.
  
  
  CONCLUSIONS
  The results of this study indicate the need for more than 7 d of diary self-report to achieve reliable estimates of total activity in older African-American and Hispanic women. The study also found that certain types of activity could be reliably estimated in less than 7 d. However, when there is less variability in the measure/behavior, the reliability is expected to be less and more measurement days are needed to achieve a desired level of reliability.
authors.affiliation: Center for Health Promotion and Prevention Research, University of Texas-Houston, 7000 Fannin Street, #2624C, Houston, TX 77030, USA. keason@sph.uth.tmc.edu
authors.forename: Karen E
authors.initials: KE
authors.lastname: Eason
authors.forename: Louise C
authors.initials: LC
authors.lastname: Masse
authors.forename: Steven H
authors.initials: SH
authors.lastname: Kelder
authors.forename: Susan R
authors.initials: SR
authors.lastname: Tortolero
mesh_terms: D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data*; D000368:Aged; D000704:Analysis of Variance; D001835:Body Weight; D003466:Cultural Characteristics; D004522:Educational Status; D002149:Energy Intake; D015444:Exercise; D005260:Female; D015438:Health Behavior / Q000208:ethnology*; D006306:Health Surveys; D006630:Hispanic or Latino / Q000706:statistics & numerical data*; D006801:Humans; D008019:Life Style / Q000208:ethnology*; D008875:Middle Aged; D012307:Risk Factors; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D014481:United States