Psychometric Properties of the Problem Areas in Diabetes (PAID) Instrument in Singapore

<div><p>Background</p><p>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.</p><p>Methods</p><p>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.</p><p>Results</p><p>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.</p><p>Conclusion</p><p>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.</p></div

Characteristics of participants in the study (N = 203).

<p>Characteristics of participants in the study (N = 203).</p

Comparison of 16-item PAID scores across known demographic, clinical and social functioning groups.

<p>¹ –Additional variables tested with non-significant differences in PAID scores–Socio-demographic groups (age, gender. Ethnicity, marital status, education, housing type, income); Clinical groups (diabetes duration); Social functioning groups (effectiveness outside work, family life satisfaction).</p><p>^{2 –}oneway ANOVA with Bonferroni corrections when multiple comparisons were made.</p><p>Comparison of 16-item PAID scores across known demographic, clinical and social functioning groups.</p

Item difficulty and fit statistics from Rasch analysis.

<p>R1c test R1c = 73.481 38 0.0005.</p><p>Andersen LR test Z = 77.248 38 0.0002.</p><p>Items with infit or outfit statistics exceeding +/-2 are in bold.</p><p>Item difficulty and fit statistics from Rasch analysis.</p

Item-person map illustrating the distribution of item difficulty along the y-axis and person ability along the x-axis.

<p>Item-person map illustrating the distribution of item difficulty along the y-axis and person ability along the x-axis.</p