Assessing mental health in primary care research using standardized scales: can it be carried out over the telephone?

Background. Telephone interviewing has economic and logistical advantages but has not been widely used in the UK. Most studies comparing face-to-face and telephone psychiatric assessment have been carried out in the US, often restricted to a population with known psychiatric disorder and involving comparisons between two separate sample groups rather than repeat interviews with the same group. The aim of the present study was to compare face-to-face and telephone administration of the 12-item General Health Questionnaire and the Revised Clinical Interview Schedule in a UK general practice sample. Method. Ninety-eight consecutive attenders at two general practices were assessed twice within 48 h. The order of face-to-face and telephone interviews was alternated. Results. There was no evidence that the mode of administration led to a bias in scores on the CIS-R. For the GHQ, those aged over 60 tended to score higher on the telephone. There was good agreement between face-to-face and telephone scores for both GHQ and CIS-R and good agreement for case definition. Participants had a strong preference for face-to-face interviews. Conclusions. Telephone assessment of mental health using the GHQ and CIS-R is a reasonable method to be used in primary care research in the UK with the limitation that telephone responses from older people might be different from face-to-face assessments for the GHQ. However, telephone interviewing appeared less acceptable and should probably be used in the context of established or ongoing personal contact between researcher and subject.