[COOP/WONCA: Reliability and validity of the test administered by telephone]

The COOP/WONCA test was initially proposed as a self-report in which the answers were supported by drawings illustrating the state investigated. Subsequent studies have confirmed its usefulness as a mere verbal self-report face-to-face administered. No data have been found about its useful when administered by telephone interview. The aim of this study was to determine the psychometric properties of the COOP / WONCA test to measure Related Quality of Life (HRQoL) administered by telephone and compare them with those obtained in other forms of prior administration.

Cross-sectional study on a random.

City of Madrid.

Random sample of 802 adult subjects, representative of the adult population in Madrid, obtained by stratification from the population census.

Questionnaire COOP/WONCA with 9 ítems included in a broader battery, administered by telephone interview.

The unrestricted factor analysis points to the unifactoriality of the scale, which measures a single latent construct (HRQOL), showing high internal consistency, not significantly different from those found by face-to-face administration, ruling out the existence of biases in the phone modality.

The COOP/WONCA test appears as a reliable and valid measure of HRQOL and telephonic administration allows to assume no changes in the results, which can reduce costs in population studies, increasing efficiency without loss of quality in the information collected.