The Validity and Reliability of the Sinhala Translation of the Patient Health Questionnaire (PHQ-9)‎ and PHQ-2 Screener

Abstract EN

The Patient Health Questionnaire (PHQ-9) was adapted and translated into Sinhala.

Sample consisted of 75 participants diagnosed with MDD according to DSM-IV criteria and 75 gender matched controls.

Concurrent validity was assessed by correlating total score of PHQ-9 with that of Centre for Epidemiological Studies Depression Scale (CESD).

The Structured Clinical Interview for DSM-IV (SCID-II) conducted by a psychiatrist was the gold standard.

Mean age of the sample was 33.0 years.

There were 91 females (60.7%).

There was significant difference in the mean PHQ-9 scores between cases (14.71) and controls (2.55) (P<0.001).

The specificity of the categorical algorithm was 0.97; the sensitivity was 0.58.

Receiver operating characteristic (ROC) analysis found that cut-off score of ≥10 had sensitivity of 0.75 and specificity of 0.97.

The area under the curve (AOC) was 0.93.

The sensitivity of the two-item screener (PHQ-2) was 0.80 and the specificity was 0.97.

Cronbach’s alpha was 0.90.

The PHQ-9 is a valid and reliable instrument for diagnosing MDD in a non-Western population.

The threshold algorithm is recommended for screening rather than the categorical algorithm.

The PHQ-2 screener has good sensitivity and specificity and is recommended as a quick screening instrument.