The Singapore Family Physician

Back to issue Vol 44 No. 2 - Vaccinations in Adults

Use of Patient Health Questionnaires (PHQ-9, PHQ-2 & PHQ-1) For Depression Screening in Singapore Primary Care

Charity Low Cheng Hong
Sharon Cohan Sung
Adrian Tan Kok Heng
Chan Yiong Huak
Daniel Fung Shuen Sheng
The Singapore Family Physician Vol 44 No 2 - Vaccinations in Adults
68 - 73
1 May 2018
0377-5305
Introduction: Depression is common and debilitating, yet treatable; however, it is often overlooked in primary care settings. The second leading cause of disease burden globally, it has significant socioeconomic consequences in Singapore. Hence there is a need for well-validated screening tools to identify depressed patients in primary care. We had previously validated the 9-item Patient Health Questionnaire (PHQ-9) against a structured interview diagnosis of major depressive disorder (Mini International Neuropsychiatric Interview) in 400 patients in a local primary care clinic . The present study was a secondary analysis undertaken to evaluate the performance of 1-and 2-item versions of the PHQ (PHQ-1 and PHQ-2) as compared to the full instrument. Results: For screening of major depression in local primary care clinic, PHQ-9 shows good validity and reliability. It had sensitivity of 91.7%, specificity of 72.2% (optimal cutoff score 6), with good internal consistency (Cronbach's alpha 0.87). Sensitivity and specificity for PHQ-2 (optimal cutoff score 2) were 91.7% and 66.8% respectively; whereas that for PHQ-1 (optimal cutoff score 1) was 83.3% and 62.9% respectively. For settings where an ultra-brief screen is preferred, PHQ-2 and PHQ-1 may be employed with limitations. Overall prevalence of major depressive disorder in this study was 3.0%.