Exploring the variation of patient-reported outcome scores across time for patients with multiple conditions: a mixed methods longitudinal study

Problem

The effect of the timing of administration or completion of patient-reported outcome measurements (PROMs) has not been studied in detail. This is despite there being evidence of the rhythmic fluctuations of symptoms people with chronic conditions experience at different time-points, making these fluctuations time-dependent (Smolensky et al 1999). Such fluctuations in symptoms can influence response to diagnostic tests and therapeutic interventions (Buttgereit et al 2015). An initial scoping review confirmed time-dependent variation in PRO scores across different chronic conditions, although there was a lack of research qualitatively exploring explanations in the variations and potential implications of time-dependent variation when collecting and interpreting PROMs data in clinical settings.

Approach

This is a mixed methods, longitudinal study spanning 9 months. The study includes interviews with 12 patients recruited from a GP practice. Patients were eligible if they were over 18 years old, diagnosed with 2 or more of the following conditions: asthma, depression and/or osteoarthritis, and able to participate in interviews. Eligible patients were asked to complete paper/electronic generic and disease-specific (only those relating to their existing conditions) patient-reported outcome measurements including PROMIS-10, Patient Health Questionnaire (PHQ-9), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Asthma Quality of Life Questionnaire (AQLQ), a week prior to their interview. Interviews focused on their PRO scores, factors that influenced their scoring during the week prior to the interview, and what external (socially determined) and internal (mood, cognitive function) factors could impact on how they report/reflect on their symptoms.

Findings

A total of 17 patients with varying comorbidities of asthma, osteoarthritis and depression. Preliminary results indicated that fluctuations of PRO scores on the disease-specific PROMs occur at different times of the day, with pain/stiffness for osteoarthritis patients at its worst in the morning and evening, asthma symptoms and depressive symptoms worse in the morning. This was influenced by external factors, mainly what activities they were involved with and weather conditions (e.g. increased pollen count). Recall of their experience of their health condition is affected by current health status, any recent attacks or hospitalisations, and mood. Additional analyses are being conducted on the interviews with full results to be presented at the conference.

Consequences

The results pose potential questions regarding when PROMs should be administered, how timing of administration can affect scores and how variability of scores should be interpreted. Consideration needs to be given to the factors impacting on patient's appraisal process of their chronic condition(s) when completing PROMs. Further implications will be considered during the talk.