In this study, the influences of patient characteristics and heterogeneity among osteoporosis patients on preferences for osteoporosis treatment were investigated. The population consisted of a heterogeneous group of patients, who considered the three attributes (1, efficacy; 2, mode (including frequency) of administration; and 3, side effects) of importance. For the attribute mode of administration, there was little difference between the subgroups. The wide range of relative importance for the attributes efficacy and side effects suggests a trade-off between efficacy and mode of administration within the subgroups. In addition, there were only limited variations in preferences between subgroups (age, gender, and having suffered from a previous fracture). Patients aged ≥ 65 preferred oral medication over intravenous medication. Patients whom have suffered from a previous fracture valued efficacy of medication more than patients without a previous fracture. There was no difference in preference between genders. In addition, three latent classes, each with its own pattern in treatment preferences, based on the patient preferences, were identified. Patients were not evenly distributed over these three classes, about two-third of patients were allocated in one class.
In two out of three latent classes, GI problems were the most disliked side effect, which is comparable with the results of Hiligsmann et al. [5, 11], and subcutaneous injections every 6 months were the preferred mode of administration. In the third latent class, skin problems were the most disliked side effect and oral tablets were the preferred mode of administration. To our knowledge, few studies have investigated the impact of covariates on preferences of osteoporosis medication, none of them comparable to our study. Therefore, we compare our outcomes with studies in which the preferences of osteoporosis patients were studied. The findings concerning other patient preferences were similar to the findings of Weiss et al., who reported that patients value effectiveness over mode and frequency of administration of medication . Our findings are however in contrast with Silverman et al. who described that age, gender, educational level, and income were associated with the preferred mode of osteoporosis treatment administration [6, 22]. In this study, other parameters, such as ethnicity and age, were included. When concerning frequency of administration, patients in latent classes 1 and 2 disliked weekly tablets which were also observed in the preferred study . This observation is important because currently weekly tablets are the preferred choice of treatment according to the current osteoporosis guidelines, but thus not the preferred treatment option by patients .
While it seems that the identification of the three latent classes is of limited clinical value, since they are not directly matched with the individual patient, it does have an important implication. As different patterns in treatment preferences were observed which cannot be related to socio-demographic or clinical patient characteristics, it would thus be important in the clinical decision-making to investigate the preference of each individual patient and involve the patient in the choice of treatment option which they feel suits their needs.
Involvement of patients in clinical decision-making could reduce the burden of non-adherence. However, health care professionals are not always able to provide patients with the proper information [25, 26]. Therefore, to assist physicians and patients with the choice regarding osteoporosis treatment and to enhance therapy adherence by involving patients in the decision-making process, a decision aid (DA) in which patients with osteoporosis can choose their preferred treatment could be a valuable addition to current treatment [27,28,29,30,31,32]. In a DA, patients are often presented with the full range of treatment possibilities and information regarding the administration of the drug, effectiveness, and side effects [33, 34]. Since preferences can differ over time, once a patient has made decision patients should be followed up regularly to check or the treatment is still in accordance with the patients’ preferences .
This study has some potential limitations. First, there were missing data, mainly concerning patient characteristics, especially for the socio-demographic parameters net household income. Since the data-collection was anonymously conducted in 2012, we were unable to clarify inconsistent answers or supplement missing data. Second, the low sample size for some of the characteristics could potentially be a limitation. Third, the questionnaires on patient characteristics and medical information were anonymously, self-completed by the patients and could not be cross-checked in, for example, medical records. Fourth, not all relevant socio-demographic and clinical characteristics were collected, such as ethnicity. The FRAX (Fracture Risk Assessment Tool) score was also not incorporated in the analysis due to the absence of data. Knowledge of the risk of a new fracture could potentially influence patient preferences .
In conclusion, this study revealed patterns in patients’ preferences for osteoporosis treatment which cannot be related to specific socio-demographic or clinical characteristics. This implicates underlying causes for the preferences which were not observed. This unique finding could be a potential entry point for additional patient preferences research, revealing latent causes influencing non-adherence.
While acknowledging the complexity of this matter and the need for further investigation, the importance of improving therapy adherence urges that patients should be offered a more active role in the choice of treatment, tailored to their preferences, fears, and believes, irrespective of their characteristics, or current treatment protocol. Active involvement of patients, for example, by using a decision aid, might lead to improved therapy adherence.