Strategies for Prescribing Analgesics Comparative Effectiveness (SPACE) Trial

Background: Chronic musculoskeletal pain conditions are among the most common problems seen in primary care. As the importance of these conditions for the health of individuals and society has been increasingly recognized, use of long-term opioid therapy for chronic musculoskeletal pain has grown exponentially. Unfortunately, research has not kept pace with this change in prescribing practice. Although evidence supports the ability of opioid analgesics to produce short-term reductions in pain intensity, long-term trials evaluating opioid effectiveness are not available. Evidence for effects of opioids on function and quality of life are limited, but observational data indicate that many patients treated with long-term opioids continue to experience severe pain and functional limitations. Furthermore, the long-term harms of opioids are poorly described in the literature. Preliminary investigations suggest a variety of potential harms related to opioid therapy, but the incidence and severity of these harms have not been well-quantified.

Objectives: The main objective of the Strategies for Prescribing Analgesics Comparative Effectiveness (SPACE) Trial is to compare benefits and harms of two prescribing strategies: 1) an opioid-intensive strategy that uses strong opioids, such as morphine, early in treatment, and 2) an opioid-avoidant strategy that optimizes non-opioid medications while delaying and minimizing opioid use. SPACE will evaluate, over 12 months, 1) effects of opioid-intensive versus opioid-avoidant prescribing strategies on pain-related function and pain intensity and 2) adverse effects of opioid-intensive versus opioid-avoidant prescribing strategies, including adverse medication-related symptoms, clinically important adverse events, and changes in physical and cognitive performance. Secondarily, the investigators will examine effects of the two prescribing strategies on health-related quality of life, pain sensitivity, and aberrant drug-related behaviors. The investigators will also conduct a secondary qualitative analysis to better understand patients' perceptions of their response to the interventions and of the value of intervention components.

Methods: SPACE is a pragmatic randomized clinical trial designed to compare the benefits and harms over 12 months of two clinically-relevant prescribing strategies for chronic musculoskeletal pain. Eligible Veterans will be those seen in primary care for chronic back or lower-extremity (hip or knee) arthritis pain who have moderate-severe pain intensity and interference with function. Those currently receiving chronic daily opioid therapy will be excluded. Participants will be randomized to the opioid-intensive (n=138) or the opioid-avoidant (n=138) arm, with stratification by primary pain location (back or hip/knee). Medications in each arm will be adjusted to target improvement in pain, while considering individual patient preferences and responses. Interventions will be delivered in a care management model using the randomly assigned prescribing strategies, automated symptom monitoring, and a structured decision-making approach to guide medication adjustment. Outcome assessors masked to treatment assignment will conduct interviews to assess patient-reported outcomes at 0, 3, 6, 9, and 12 months and will assess physical performance and cognitive function at 0, 6, and 12 months. For the primary outcome, the Brief Pain Inventory (BPI) Interference scale, the study will have 80% power to detect a 1 point difference between groups, assuming 2-sided alpha=0.05 and 20% attrition. Analysis will use an intent-to-treat approach, including all participants in the arm to which they were originally assigned.