Psychometric Properties of the Problem Areas in Diabetes (PAID) Instrument in Singapore.
BACKGROUND
Emotional distress is an important dimension in diabetes, and several instruments have been developed to measure this aspect. The Problem Areas in Diabetes (PAID) scale is one such instrument which has demonstrated validity and reliability in Western populations, but its psychometric properties in Asian populations have not been examined.


METHODS
This was a secondary analysis of data from patients with Type 2 diabetes mellitus recruited through convenience sampling from a diabetes specialist outpatient clinic in Singapore. The following psychometric properties were assessed: Construct validity through confirmatory factor analysis (CFA) and Rasch analysis, concurrent validity through correlation with related scales (Kessler Psychological Distress Scale, Diabetes Health Profile-psychological distress, Audit of Diabetes Dependent Quality of Life), reliability through assessment of internal consistency and floor and ceiling effects, and sensitivity by estimating effect sizes for known clinical and social functioning groups.


RESULTS
203 patients with mean age of 45±12 years were analysed. None of the previously published model structures achieved a good fit on CFA. On Rasch analysis, four items showed poor fit and were removed. The abridged 16-item PAID mapped to a single latent trait, with a high degree of internal consistency (Cronbach ɑ 0.95), but significant floor effect (24.6% scoring at floor). Both 20-item and 16-item PAID scores were moderately correlated with scores of related scales, and sensitive to differences in clinical and social functioning groups, with large effect sizes for glycemic control and diabetes related complications, nephropathy and neuropathy.


CONCLUSIONS
The abridged 16-item PAID measures a single latent trait of emotional distress due to diabetes whereas the 20-item PAID appears to measures more than one latent trait. However, both the 16-item and 20-item PAID versions are valid, reliable and sensitive for use among Singaporean patients with diabetes.
Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore.
Kavita
K
Venkataraman
Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore.
Luor Shyuan Maudrene
LS
Tan
Center for Quantitative Medicine, Duke NUS Graduate Medical School, Singapore, Singapore; Singapore Clinical Research Institute, Singapore, Singapore.
Dianne Carrol Tan
DC
Bautista
Department of Psychology, National University of Singapore, Singapore, Singapore.
Konstadina
K
Griva
Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Yasmin Laura Marie
YL
Zuniga
Department of Psychology, National University of Singapore, Singapore, Singapore.
Mohamed
M
Amir
Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Khoo Teck Puat-National University Children's Medical Institute, National University Hospital, Singapore, Singapore; Singapore Institute for Clinical Sciences, A*STAR, Singapore, Singapore.
Yung Seng
YS
Lee
Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore.
Jeannette
J
Lee
Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore; Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
E Shyong
ES
Tai
Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Eric Yin Hao
EY
Khoo
Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore; Department of Pharmacy, National University of Singapore, Singapore, Singapore.
Hwee Lin
HL
Wee
D000328:Adult; D003922:Diabetes Mellitus, Type 1 / Q000523:psychology*; D003924:Diabetes Mellitus, Type 2 / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D015203:Reproducibility of Results; D012846:Singapore; D013315:Stress, Psychological