Blending qualitative and quantitative research methods to optimize patient reported outcome measures (PROMs)

Patient-reported outcome measures (PROMs) are used widely within the addictions field. Their value could be increased by greater use of qualitative methods incorporating patients’ perspectives. Qualitative methods can also add value to the quantitative scores produced by PROMs. Patient-reported outcome measures (PROMs) are self-completion questionnaires that assess a patient's health status or health-related quality of life at a single time-point. They can be used for many purposes, including baseline recording, gauging treatment needs, monitoring patient progress, evaluating clinical outcomes and helping to understand mechanisms of behaviour change. PROMs can be generic [e.g. the Short-Form 36 (SF-36)] or condition-specific [e.g. the Arthritis Impact Measurement Scales (AIMS)] 1. Within the addictions, PROMs have been used widely; for example, to measure cravings [e.g. the Minnesota Cocaine Craving Scale (MCCS)], withdrawal symptoms (e.g. the Mood and Physical Symptoms scale) and dependence [e.g. Severity of Dependence Scale (SDS)]. PROMs are often (but not always) designed using qualitative methods and with the patient perspective in mind. The use of qualitative research in PROM development is recommended by the Cochrane Handbook for Systematic Reviews of Interventions 2. This states that the concepts used in a PROM (e.g. craving, withdrawal, dependence, tolerance, intensity, distress, recovery) should be elicited from the target population and patients should be involved in generating the questions used in a PROM to ensure that all relevant aspects of those concepts are captured (i.e. that the PROM has good content validity) 2. The involvement of patients is also crucial, given that professionals’ assessments of their patients’ treatment needs and health status often differ from their patients’ own assessments, and patients and professionals may disagree about the relative importance of specific health outcomes 3-7. Furthermore, this mismatch may change over time. In designing PROMs, we therefore need early and meaningful engagement with purposively selected groups of patients and/or service users through in-depth interviews, focus groups or other open consultation processes. Without this, the concepts, domains and questions used by researchers and clinicians may not be meaningful or relevant to the people whose condition is being assessed 8. Equally, PROMs may try to measure inappropriate, contradictory or objectionable outcomes or use ambiguous and unclear language that deters completion or generates unreliable results 7. When assessing aspects of addiction, a remotely constructed measure, however scientifically valuable, may inadvertently alienate patients by presuming certain negative behaviours or attributes (such as criminal activity, immorality or lack of control) or using language that is experienced as stigmatizing (such as ‘abuse’, ‘addict’, ‘sick’ or ‘deviant’) 7. Cognitive interviewing—a qualitative technique that involves asking respondents to think out loud as they complete a structured questionnaire—is a particularly valuable method that can be used in PROM design to pretest and improve questions that may be sensitive, intrusive or too difficult for some individuals to understand 9. It is not that patients’ self-reports are more important than assessments made by clinicians; nor are they more accurate than objectively measured outcomes. It is also not the case that PROMs, even those developed with and by patients, provide the definitive approach for assessing an individual's health status or health-related quality of life. Even with extensive qualitative and consultative groundwork, PROMs can still fail to capture important aspects of an individual patient's experiences. Knowing whether or not someone has stopped craving drugs is valuable, but cannot reveal whether or not they are pleased with this change in health status. Scores relating to a particular health outcome, or aspect of a health outcome, may mean very different things to different people at different times. Some smokers may fear weight gain more than lung disease, while some drinkers may be deterred from excessive alcohol consumption more by erectile dysfunction than by gastritis. In order to appreciate fully the numerical scores produced by PROMs, supplementary narratives, descriptions or analysis arising from verbal reports will often be required. Our own ongoing experiences of developing a PROM for addiction recovery find that patients enjoy completing a structured questionnaire that captures important aspects of their lives. Nonetheless, they are seldom content to tick a response box and then move silently and mechanistically on to the next question. Instead, they want to discuss their responses, often reflecting on how they might have answered the question differently in different circumstances. These accompanying PROM narratives provide valuable contextual information that might be used to frame subsequent therapeutic work within clinical practice. Equally, they might be analysed using standard qualitative techniques to complement and expand upon the quantitative PROM scores. Robust PROMs are not therefore simply the product of good mixed-methods research; they can also generate valuable mixed-methods data. Combining closed PROM questions with open qualitative prompts and probes that capture individuals’ personal perspectives seems to offer the optimal way of understanding and measuring patient reported outcomes of addiction and its related constructs. J.N. is part-funded by, and J.S. also receives support from, the National Institute for Health Research (NIHR) Biomedical Research Centre for Mental Health at South London and Maudsley NHS Foundation Trust and King's College London. J.S. is a clinician and has had, and continues to have, clinical responsibilities and has also worked with a range of types of treatment and rehabilitation service providers. He has also worked with pharmaceutical companies to seek to identify new or improved treatments, and also with a range of governmental and non-governmental organizations. A fuller account is given on his personal web-page of the Addictions Department of King's College London at http://www.kcl.ac.uk/ioppn/depts/addictions/people/hod.aspx. The views expressed are those of the authors and not necessarily those of the NIHR or the Department of Health.