Introduction
Why patient-reported outcomes?
PROs are key measures of treatment outcomes in some disease areas
Description of PROs
Condition-specific Measure or Instrument
| A category of health measures that describes problems such as low-back pain or particular interventions or treatments such as knee-replacement or coronary artery bypass graft surgery. |
Disease-Specific Measure or Instrument
| A category of health measures of severity, symptoms, or functional limitations that are specific to a particular disease state, condition, or diagnostic grouping; for example, arthritis or diabetes. |
Domain (also known as dimension) | PROs often have domains or dimensions as subcategories. For instance, the SF-36, a very popular instrument, has 8 domains or dimensions. Examples of domains defined for the SF-36 include: physical role functioning, social role functioning, emotional role functioning, and mental health. An alternative, less satisfactory designation is “subscale”. |
Functional Status
| An individual’s effective performance or ability to perform those roles, tasks, or activities that are valued, e.g. going to work, playing sports, or maintaining the house. Most often, functional status is divided into physical, emotional, mental, and social domains, although much finer distinctions are possible. Deviations from usual performance or ability indicate dysfunction. |
Generic Measure
| A measure designed for use with any illness groups or population samples, as opposed to those intended for specific illness groups. |
Health-Related Quality of Life
| Personal health status. It usually refers to aspects of our lives that are dominated or significantly influenced by our mental or physical well-being. |
Patient Satisfaction
| A consequence of the use of healthcare products, services or programs that affect patients’ satisfaction with health or healthcare. |
Quality of life
| An evaluation of all aspects of our lives, including, for example, where we live, how we live, and how we play. It encompasses such life factors as family circumstances, finances, housing and job satisfaction. |
Self-reported Symptoms
| Symptoms, which are directly reported by the patient by means of questionnaires, diaries, hand held devices or web-based forms. |
Well-Being
| Subjective bodily and emotional states; how an individual feels; a state of mind distinct from functioning that pertains to behaviours and activities. |
Measure | Strengths | Weaknesses |
---|---|---|
Types of Scores Produced
| ||
Single indicator number | Global evaluation | May be difficult to interpret |
Useful for population | ||
Single index number | Represents net impact | Sometimes not possible to disaggregate contribution of domains to the overall score |
Useful for cost effectiveness | ||
Profile of interrelated scores | Single instrument | Length may be a problem |
Contribution of domains to overall score possible | May not have overall score | |
Battery of independent scores | Wide range of relevant outcomes possible | Cannot relate different outcomes to common measurement scale |
May need to adjust for multiple comparisons | ||
May need to identify the major outcome | ||
Range of Populations and Concepts | ||
Generic: applied across diseases, conditions, populations, and concepts | Broadly applicable | May not be responsive to change |
Summarizes range of concepts | May not have focus of patient interest | |
Detection of unanticipated effects possible | Length may be a problem | |
Effects may be difficult to interpret | ||
Specific: applied to individuals, diseases, conditions, populations, or concepts/domains | More acceptable to respondents | Cannot compare across conditions or populations |
May be more responsive to change | Cannot detect unanticipated effects | |
Weighting System
| ||
Utility: preference weights from patients, providers, or community | Interval scale | May have difficulty obtaining weights |
Patient or consumer view incorporated | May not differ from statistical weights that are easier to obtain | |
Equal-weighting: items weighted equally or from frequency or responses | Self-weighting samples | May be influenced by prevalence |
More familiar techniques | Cannot incorporate tradeoffs | |
Appears easier to use |