Outcome measurements in mental health services is beneficial in allowing healthcare providers in determining the effectiveness of their treatment plan. Health of the Nation Outcome Scale (HoNOS) and Global Assessment of Functioning (GAF) are two well-established instruments to measure patients’ outcome.

To measure the correlation of these two scales, and the feasibility of HoNOS.

Prospective longitudinal study of psychiatric outpatients attending a clinic in Sligo. Patients were assessed using HoNOS and GAF by trained doctors during the consultation. Feedback from doctors using HoNOS during the research was taken as a measure for feasibility.

Total of 441 HoNOS and 237 GAF completed on 280 patients (53.2% female, mean age 46.23; SD = 14.89). The correlation between HoNOS and GAF was (r = –0.696, P < 0.001). In reassessment, we found significant reduction in HoNOS score when comparing the first assessment with the second (t = 4.590, df = 110, P < 0.01) and the third (t = 2.876, df = 37, P < 0.01). Using a linear mixed-effects model, it was found that patients with diagnosis of schizophrenia, mood affective disorder, neurotic disorder, personality disorder and younger in age are more likely to improve during the follow-up compared to those with organic mental disorders, alcohol related problems and older age.

HoNOS is a feasible scale and can be potentially used as an outcome measurement in the mental health services. Can help in deciding better management plan for patient and improvement of the service. HoNOs can also be used for comparison of outcomes between services in national and international level.

The authors have not supplied their declaration of competing interest.