A staging approach to measuring patient-centred subjective outcomes

Introduction: In assessing clinical change, measurement is often based on psychometric scales. However, change is best revealed within the constellation of problems salient to the patient, rather than in alterations in the abstract constructs, psychometrically measured. These patients' problems often serially unfold in qualitative stages, even before the full-blown disorder emerges. These qualitative stages constitute the natural history extending from early to late, fluctuating from mild to severe, and progressing from full-blown disorder to recovery. Method: We reviewed the literature on clinimetrics and patient-centred subjective measures, and related these findings to the use of the discretized-analogue scaling method. Results: There is increasing recognition of clinimetric approaches that structure the pre-clinical and clinical material into a scale that reflects the symptoms, consequences and complications in a manner understandable to the patient, and enabling the quantification of severity or change. This monograph provides criteria and methods for developing these building blocks that enable the assessment of severity, stage or change. We show examples of their use in quantitative clinical outcome measurement. Conclusion: We encourage further studies in the ideology and procedures for measuring clinical change in terms of personally subjective experiences.