Preferences for risks and benefits of treatment outcomes for chronic low back pain: Choice-based conjoint measure development and discrete choice experiment

Abstract

Introduction: Understanding individual patient preferences for chronic low back pain (cLBP) outcomes is essential for targeting available therapeutic options; yet tools to elicit patient outcome preferences are limited.

Objective: To develop and test a choice-based conjoint (CBC) measure, commonly used in behavioral economics research, to elicit what outcomes patients with cLBP want to achieve and avoid.

Design: We developed a survey-based CBC measure to allow patients to make risk/benefit trade-off choices between possible treatment outcomes. After extensive literature, clinician, and patient input, our measure included seven attributes: fatigue, anxiety/depression, difficulty thinking/making decisions, pain intensity, physical abilities, change in pain, and ability to enjoy life despite pain. Random-parameters logit models were used to estimate strength of preferences, and latent class analysis was used to identify patient characteristics associated with distinct preference.

Setting: Online study using the Sawtooth web-based platform.

Participants: Two hundred eleven individuals with cLBP recruited from online advertising as well as at clinical sites across multiple academic and private institutions.

Interventions: Not applicable.

Results: The most valued outcome was the highest level of physical activity (β = 1.6-1.98; p < .001), followed by avoiding cognitive difficulties (β = -1.48; p < .001). Avoidance of severe pain was comparable to avoiding constant fatigue and near-constant depression/anxiety (β = -0.99, -1.02); p < .001). There was an association between preferences and current pain/disability status; patients with higher pain had a stronger preference to avoid severe pain, whereas those with higher disability have stronger preferences for achieving physical activity. The latent class analysis identified two distinct groups: (1) more risk-seeking and willing to accept worse outcomes (56%); and (2) more risk-averse with a stronger preference for achieving maximum benefits (44%).

Conclusions: Our study illuminated cLBP patient preferences for treatment outcomes and heterogeneity in these preferences. Patients stressed the importance of reaching high physical activity and avoiding cognitive declines, even over a desire to avoid pain. More work is needed to understand patient preferences to aid informed, shared decisions.

Figure 1A.

Preference Weights for Living with Outcomes of Chronic Low Back Pain. N=205 Note: The orange values are significant at P<0.05 level. Subgroup analysis, by high vs low pain intensity High Pain Intensity n=54, Low Pain Intensity n=58; Note: The bolded numbers indicate a P value that is significant at at least 0.05 level Subgroup analysis, by high vs low disability score Low Disability n=156, Severe Disability n=49; Note: The red numbers indicate a P value that is significant at at least 0.05 level Low Income n=85; High Income n=65 Note: The bolded numbers indicate a P value that is significant at at least 0.05 level

Figure 1A.

Preference Weights for Living with Outcomes of Chronic Low Back Pain. N=205 Note: The orange values are significant at P<0.05 level. Subgroup analysis, by high vs low pain intensity High Pain Intensity n=54, Low Pain Intensity n=58; Note: The bolded numbers indicate a P value that is significant at at least 0.05 level Subgroup analysis, by high vs low disability score Low Disability n=156, Severe Disability n=49; Note: The red numbers indicate a P value that is significant at at least 0.05 level Low Income n=85; High Income n=65 Note: The bolded numbers indicate a P value that is significant at at least 0.05 level

Figure 1A.

Preference Weights for Living with Outcomes of Chronic Low Back Pain. N=205 Note: The orange values are significant at P<0.05 level. Subgroup analysis, by high vs low pain intensity High Pain Intensity n=54, Low Pain Intensity n=58; Note: The bolded numbers indicate a P value that is significant at at least 0.05 level Subgroup analysis, by high vs low disability score Low Disability n=156, Severe Disability n=49; Note: The red numbers indicate a P value that is significant at at least 0.05 level Low Income n=85; High Income n=65 Note: The bolded numbers indicate a P value that is significant at at least 0.05 level

Figure 2.

Preference Weights, by Latent Class, with Controls as coefficients N=205 Note: The bolded numbers indicate a P value that is significant at the 0.05 level or greater Note: Those age 30 (59%) vs age 75 and those with low incomes (65%) and with a high total PEG score (60%) were more likely to belong to class I (56% of the participants), which is more risk accepting and willing to accept lower outcome levels compared with class II individuals who were more risk averse and preferred to achieve maximum outcomes (44% of the participants). Those in class II had a four- to six-fold stronger preference for attaining all levels of physical activity (β = 3.23 vs 0.462 for ability to bike or walk at least 1 mile), a two-fold stronger preference for avoiding severe pain (β =−1.055 vs −0.666), and a two-fold stronger preference for avoiding cognitive difficulty (β =−1.579 vs −0.834 for avoiding much difficulty with thinking). Class I had stronger preference to avoid fatigue (β =−.301 vs −0.110 for avoiding fatigue sometimes and β=−0.877 vs −0.638 for avoiding fatigue all the time).