Background Adherence with osteoporosis medications is poor and suboptimal. Understanding patients’ preferences may be a first step to improve adherence with therapy. Over recent years, there has been an increased interest in the use of discrete-choice experiments (DCE) to elicit preferences. The number of medication attributes identified in the literature however exceeds what one may find possible to pilot in a DCE. Hence there is a need to gain insight into the most relevant attributes for osteoporosis treatment.
Objectives This study aims to test the feasibility of using a nominal group technique (NGT) to prioritize and evaluate the relative importance of attributes for osteoporosis medication among adult patients.
Methods Five group discussions of 4-8 adult osteoporotic patients each (total=26) were conducted in Belgium and the Netherlands. Patients were selected to represent the full clinical spectrum of ages, educational level and history of osteoporosis. Twelve potentially important attributes for osteoporosis drug therapy were established from literature review and expert discussions. The NGT consisted of three steps: (1) an individual ranking of the twelve attributes by importance from 1 to 12, (2) a group discussion on each of the attributes including a group review of the aggregate score of the initial rankings, and (3) a second ranking task of the same attributes. Group discussions were conducted by a medical trainee in rheumatology, observed by a moderator and were tape recorded. The individual rankings were then summed across participants to derive the ranking of the attributes first for each group and next for all patients.
Results After five group discussions, the rank order of the attributes did not change anymore. Although eighty percent of the patients changed their ranking after the discussion; the initial and final ranking did not markedly differ, with two exceptions. The importance of mode of action was reduced after discussions (from position 5 to position 8), while the out-of-pocket costs increased from position 10 to 5. It was also observed that fifteen percent of patients did not correctly rank from 1 to 12, and that the order of presenting of attributes in the rank system played a role in the ranking. Effectiveness was the most important medication attribute, followed by side-effects, frequency of administration and mode of administration, respectively. While out-of-pocket costs, time on market, place of administration (such as hospital, home) and the need for sequential treatment were of some relevance, costs for society, mode of action, combination treatment and brand/generic specification did not reach the top three most important attributes in any of the groups. Out-of-pocket was not in the top four in the Dutch groups reflecting that, in contrast with Belgian patients, they have no out-of-pocket contribution for medications. Differences between group and aggregate individual analyses were small.
Conclusions A nominal group technique is feasible and reliable for prioritizing attributes from the patients’ perspective. Results from this study will be used to develop a DCE to further quantify patients’ preferences for osteoporosis treatment as an important step towards improving adherence to treatment.
Disclosure of Interest M. Hiligsmann Grant/Research support from: Amgen, C. van Durme: None Declared, P. Geusens: None Declared, B. Dellaert: None Declared, C. Dirksen: None Declared, T. van der Weijden: None Declared, J.-Y. Reginster: None Declared, A. Boonen: None Declared