Arcadio Erlicher, Senior Consultant Psychiatrist Dipartimento di Salute Mentale, Ospedale Niguarda Ca' Granda, Milan, Italy
Assessing reliable and clinically significant change on Health of the Nation Outcome Scales: method for displaying longitudinal data
Article first published online: 28 JUL 2005
Australian and New Zealand Journal of Psychiatry
Volume 39, Issue 8, pages 719–725, August 2005
How to Cite
Parabiaghi, A., Barbato, A., D'Avanzo, B., Erlicher, A. and Lora, A. (2005), Assessing reliable and clinically significant change on Health of the Nation Outcome Scales: method for displaying longitudinal data. Australian and New Zealand Journal of Psychiatry, 39: 719–725. doi: 10.1111/j.1440-1614.2005.01656.x
Antonio Lora, Senior Consultant Psychiatrist Servizio Psichiatrico di Diagnosi e Cura, Ospedale di Desio, Milan, Italy
- Issue published online: 28 JUL 2005
- Article first published online: 28 JUL 2005
- Received 13 December 2004; revised 4 February 2005; accepted 25 February 2005.
- clinical significance;
- longitudinal study;
- measuring change;
- reliable change
Objective: Many authors recommended that reliable and clinically significant change (RCSC) should be calculated when reporting results of interventions. To test the reliability of the Health of the Nation Outcome Scales (HoNOS) in identifying RCSC, we applied the Jacobson and Truax model to two HoNOS assessments in a large group of people evaluated in 10 community mental health services in Lombardy, Italy, in 2000.
Method: The HoNOS was administered to 9817 patients; of these, 4759 (48%) were re-assessed. Reliable change (RC) was calculated using Cronbach's alpha (α), as a parameter of the reliability of the measure. Clinical significance cut-offs were calculated using a classification of severity based on HoNOS items.
Results: In the whole sample, the clinical improvement cut-off was 11 and the remission cut-off was 5. Considering the severe patients, the clinical improvement cut-off was 12. The RC index calculated on the whole group and on the subgroup of severe patients indicated that eight-point and seven-point changes, respectively, were needed to be confident that a real change had occurred. Longitudinal changes were depicted on two-dimensional graphs as examples of reporting RCSC on HoNOS total scores in a routine data collection: 91.6% of the whole sample (4361) was stable, 5.6% (269) improved and 1.8% (129) worsened.
Conclusion: Our study proposes a methodological framework for computing RCSC normative data on a widely used outcome scale and for identifying different degrees of clinical change.