Patient preference and willingness to pay for knee osteoarthritis treatments

Abstract

Purpose: To review treatments for osteoarthritis of the knee (OAK) received by patients across five European countries, and to obtain patients' perceptions and willingness to pay for current treatments.

Patients and methods: A prospective, internet-based, double-blind survey of adults with OAK was conducted in France, Germany, Italy, Spain, and the United Kingdom. The questionnaire included questions about diagnosis, treatment history, and perceptions of OAK treatments, followed by a discrete choice-based conjoint exercise to identify preferred attributes of OAK treatments, evaluating 14 sets of four unbranded products.

Results: Two thousand and seventy-three patients with self-reported OAK completed the survey; 17.4% of patients rated their knee pain as drastically affecting their ability to perform normal daily activities, and 39.3% of employed patients reported that they had lost work time because of OAK. The most common treatments were exercise (69.7%), physical therapy (68.2%), and nonprescription oral pain medication (73.9%). Treatments perceived as most effective were: viscosupplement injections (74.1%), narcotics (67.8%), and steroid injection (67.6%). Patient co-pay, duration of pain relief, and type of therapy exhibited the largest impact on patient preference for OAK treatments. The average patient was willing to pay €35 and €64 more in co-pay for steroid and viscosupplement injections, respectively, over the cost of oral over-the-counter painkillers (per treatment course, per knee) (each P<0.05).

Conclusion: OAK is a debilitating condition that affects normal daily activities. In general, treatments most commonly offered to patients are not those perceived as being the most effective. Patients are willing to pay a premium for treatments that they perceive as being more effective and result in longer-lasting pain relief, and those that can be administered with fewer visits to a physician.

Keywords: osteoarthritis; survey; treatment; viscosupplementation.

Figure 1

Impact of varying the type of treatment upon utility premium. Notes: The differences between adjacent utilities indicate the relative importance of moving from one level (type of treatment) to an adjacent level. Error bars indicate 95% confidence interval. Abbreviations: OTC, over the counter; Rx, medical prescription; VS, viscosupplement.

Figure 2

Impact of varying attributes of patient characteristics upon their choice of OAK treatment. Note: Error bars indicate 95% confidence interval. Abbreviations: mo, month/s; OAK, osteoarthritis of the knee.

Figure 3

Patient factors linked to preference for VS injections over oral OTC. Note: Error bars indicate 95% confidence interval. Abbreviations: GI, gastrointestinal; OTC, over the counter; VS, viscosupplement.