title: Worry about performance: a unique dimension of caregiver burden.
abstract: BACKGROUND
  Recent studies that describe the multidimensionality of the Zarit Burden Interview (ZBI) challenge the traditional dual-factor paradigm of personal and role strains (Whitlatch et al., 1991). These studies consistently reported a distinct dimension of worry about caregiver performance (WaP) comprising items 20 and 21.The present study aims to compare WaP against conventional ZBI domains in a predominantly Chinese multi-ethnic Asian population.
  
  
  METHODS
  We studied 130 consecutive dyads of family caregivers and patients. Factor analysis of the 22-item ZBI revealed four factors of burden. We compared WaP (factor 4) with the other three factors, personal strain, and role strain via: internal consistency; inter-factor correlation; item-to-total ratio across Clinical Dementia Rating (CDR) stages; predictors of burden; and interaction effect on total ZBI score using two-way analysis of variance.
  
  
  RESULTS
  WaP correlated poorly with the other factors (r = 0.05-0.21). It had the highest internal consistency (Cronbach's α = 0.92) among the factors. Unlike other factors, WaP was highly endorsed in mild cognitive impairment and did not increase linearly with disease severity, peaking at CDR 1. Multiple regression revealed younger caregiver age as the major predictor of WaP, compared with behavioral and functional problems for other factors. There was a significant interaction between WaP and psychological strain (p = 0.025).
  
  
  CONCLUSIONS
  Our results corroborate earlier studies that WaP is a distinct burden dimension not correspondent with traditional ZBI domains. WaP is germane to many Asian societies where obligation values to care for family members are strongly influential. Further studies are needed to better delineate the construct of WaP.
authors.affiliation: Cognition and Memory Disorders Service, Department of Geriatric Medicine, Tan Tock Seng Hospital, Singapore.
authors.forename: Wee Shiong
authors.initials: WS
authors.lastname: Lim
authors.affiliation: Department of Medicine, Taiping Hospital, Taiping, Malaysia.
authors.forename: Wee Kooi
authors.initials: WK
authors.lastname: Cheah
authors.affiliation: Cognition and Memory Disorders Service, Department of Geriatric Medicine, Tan Tock Seng Hospital, Singapore.
authors.forename: Noorhazlina
authors.initials: N
authors.lastname: Ali
authors.affiliation: Nursing Service, Tan Tock Seng Hospital, Novena, Singapore.
authors.forename: Huey Charn
authors.initials: HC
authors.lastname: Han
authors.affiliation: Nursing Service, Tan Tock Seng Hospital, Novena, Singapore.
authors.forename: Philomena Vasantha
authors.initials: PV
authors.lastname: Anthony
authors.affiliation: Cognition and Memory Disorders Service, Department of Geriatric Medicine, Tan Tock Seng Hospital, Singapore.
authors.forename: Mark
authors.initials: M
authors.lastname: Chan
authors.affiliation: Cognition and Memory Disorders Service, Department of Geriatric Medicine, Tan Tock Seng Hospital, Singapore.
authors.forename: Mei Sian
authors.initials: MS
authors.lastname: Chong
mesh_terms: D000223:Adaptation, Psychological; D000368:Aged; D000369:Aged, 80 and over; D001007:Anxiety; D044466:Asian People / Q000208:ethnology / Q000523:psychology; D017028:Caregivers / Q000523:psychology*; D002681:China; D017281:Cost of Illness; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007406:Interview, Psychological; D008297:Male; D016743:Mental Competency; D008875:Middle Aged; D011237:Predictive Value of Tests; D011569:Psychiatric Status Rating Scales; D015203:Reproducibility of Results; D013315:Stress, Psychological; D011795:Surveys and Questionnaires