OBJECTIVES: Different instruments are available to assess health in individuals with psychotic illness. We aimed to identify the complementary value of some different instruments to assess health and health changes in schizophrenic patients. METHODS: We analysed data from a naturalistic, prospective cohort study, called COMETA, which involved 637 patients aged 18-40 years, 65.0% male, with schizophrenia (86.5%) or schizophreniform disorder (13.5%), enrolled in 2006-2007 and followed up to 52 weeks. Symptoms and functional changes were assessed with the physicians’ rated scales Positive-And-Negative-Syndrome-Scale (PANSS), Global-Assessment-of-Functioning (GAF), Clinical-Global-Impression-Severity (CGI-S). The physicians’ opinion was asked to assess compliance toward antipsychotic treatment. Patients reported their attitude toward treatment with the Drug-Attitude-Inventory (DAI-30). QoL was assessed with EQ-5D and SF-36. We investigated whether relationships exist between scores obtained from the different scales. RESULTS: At enrolment, significant correlations were found between PANSS, GAF, CGI-S scores (r, absolute value=0.674-0.766). Every QoL score significantly correlated each other (r=0.360-0.582). Correlations were lower between QoL and clinical scores (0.189-0.393). Low correlations were estimated between QoL scores and physicians’ reported compliance (r=0.113-0.282) or DAI-30 score (0.142-0.274). Each instrument showed an average improvement in the patients’ condition after 52 weeks. However, scarce correlation was found between clinicians’ and patients’ reported changes. CONCLUSIONS: Both clinicians’ and patients’ reported outcomes are necessary for a complete evaluation of schizophrenic patients’ health. Furthermore, its brevity, and its immediateness of data reading and interpretation are reasons for considering its introduction into the physicians’ armamentarium for practice.