Can an Acute Pain Service Be Cost-Effective?

In many countries around the world, the anesthesiologist is the primary physician responsible for pain control in the first 24 hours after surgery. However, in the United States of America (USA), postoperative analgesia is typically managed by the surgeon. This is because their professional fee includes this responsibility while the patient remains in the hospital and when the patient returns home. At the other end of the spectrum is a dedicated Acute Pain Service team with expertise and authority for managing a patient's surgical pain. The well-done randomized clinical trial conducted by Lee et al.1 and described in this issue of the journal estimates the cost-effectiveness of an anesthesiologist-led, nurse-based Acute Pain Service, mainly charged with managing IV patient-controlled analgesia. The control group consisted of patients receiving IM or IV boluses of opioids as needed by nurses on the ward.1 It is not known how frequently this technique is used in other parts of the world, including the USA. Our objectives for this editorial were to: Estimate the total annual number of surgical inpatients in the USA that might benefit from care provided by an Acute Pain Service. Define possible structures and functions of an Acute Pain Service because these may vary among institutions, and affect the economic viability of such a service. Outline research questions that deserve further study to help hospitals make the needed investment in an Acute Pain Service. HOW MANY PATIENTS ARE AT RISK FOR PAIN AFTER INPATIENT SURGERY IN THE USA? To obtain an estimate of the number of inpatients having surgery, the Nationwide Inpatient Sample from the Healthcare Cost and Utilization Project was used. It samples 20% of inpatient discharges from 1056 academic, community, and acute care hospitals in 42 states, and is intended to be representative of 90% of all hospital discharges in the USA. For 2008, the year with the most recently available data, there were approximately 9.1 million inpatients having surgery in the USA. This constitutes approximately 23% of all inpatient visits, and a 4% annual growth rate since 1998 (Table 1). These data exclude federal and prison hospitals.Table 1: Thirty Most Common Diagnosis Related Groups for Inpatients Having Surgery Requiring AnesthesiaThe data in Table 1 provide insight into the size and scope of the demand for pain management in the postoperative setting. From a national health policy perspective, there are many different surgical procedures.2 However, cesarean deliveries, orthopedics, and general surgery procedures should be a priority for optimizing clinical acute postoperative pain care because they account for a large fraction of all inpatient surgery. With public and private payers continuing to face tightening budgets, and with single bundled episode of care payments for hospital and physician care looming, it is an opportunity for anesthesiologists to consider additional venues where the specialty can provide value. The dedicated Acute Pain Service seems to be a logical choice, given that it is a straightforward extension of the care anesthesiologists already provide in the operating room and chronic pain settings. However, given the expenses of such a service, what are the incentives for hospitals and anesthesiologists to participate? On the clinical side, controlling pain is of importance to patients, a goal made more difficult by the increasing number of patients who are admitted with chronic pain syndromes including opioid prescriptions superimposed on their acute surgical pain. The potential clinical benefits of a dedicated Acute Pain Service have resulted in support from a variety of organizations such as the American Society of Anesthesiologists,3 the Royal College of Surgeons, and the College of Anesthetists. In addition to these clinical benefits, an Acute Pain Service provides important visibility to the anesthesia group within a hospital. Patient satisfaction with pain control comprises an important component of many measures of hospital quality, such as Press Ganey scores. Many facilities are providing resources to an Acute Pain Service to increase these scores. In fact, a patient's Press Ganey response to, “How well your pain was controlled” was the second most important variable correlated to whether a patient recommended the hospital to someone else. By the way, the number one item was “Staff worked together to care for you.”4 POSSIBLE STRUCTURES AND FUNCTIONS OF AN ACUTE PAIN SERVICE Despite these benefits, the use of a dedicated Acute Pain Service to manage postoperative pain did not gain widespread adoption in the 1990s in the USA5–7 or abroad.8,9 Sometimes Acute Pain Services are services in name only. For example, 36% of 446 hospitals in Germany operated an Acute Pain Service but half did not have specific personnel assigned to the service, policies for nights and weekends, written protocols for pain management, or regular assessment and documentation of pain scores at least once a day.10 The challenges are in part financial, such as how coding/billing affects profitability, but also include organizational change barriers such as competing managerial and clinical agendas, staff shortages, local politics, professional hierarchies, and workload changes.11 In Italy, although 42% of 163 public hospitals had an organized Acute Pain Service, continuous IV analgesia using elastomeric infusion systems was the most frequently used analgesic technique, and IV patient-controlled analgesia and epidural techniques were used in fewer than 14% of patients.12 In Ireland, a 2007 study showed that 71% of teaching hospitals had a formalized Acute Pain Service, of which 85% were established after 1990.13 Moreover, where a dedicated Acute Pain Service exists, there is variability in its structure and the types of services it provides. To illustrate the variability in Acute Pain Service staffing and services provided at several USA hospitals, we created Table 2, which is based on informal communication with colleagues at those facilities.Table 2: Staffing and Care Provided by Acute Pain ServicesThe heterogeneity in structure and function of pain services across facilities makes it difficult to state unequivocally whether an Acute Pain Service is or is not cost-effective. To define the exact nature of an Acute Pain Service is a crucial component of its economic study. Anesthesia groups in the USA currently are likely to provide an Acute Pain Service for a variety of reasons such as: An anesthesia residency training program exists at the hospital. As of 2008, a month-long acute pain experience for anesthesia trainees is required. A hospital's practice is to place a large number of peripheral nerve catheters, which then extends the anesthesiologist's responsibility longer and leads to an Acute Pain Service. The anesthesia group is paid for its service by third party payers such as the federal government or private insurance, and the marginal revenue exceeds the marginal costs. The anesthesia group's contract and professional service agreement with the hospital stipulates its existence. The hospital may subsidize the Acute Pain Service budget if there is a perceived competitive advantage to the hospital to attract more cases. The surgeons' desire to deflect the night phone calls and pain control questions to the anesthesia group especially if the anesthesia group is being paid for taking calls (depending on the contract) whereas the surgeons are not. Financial considerations are often largely responsible for the slow adoption of a dedicated Acute Pain Service. Although the study by Lee et al. in this issue of the journal, along with the studies that preceded it,14 represent important first steps, more research is needed to find ways to overcome organizational constraints and deliver the specialized care of an Acute Pain Service in an economically viable manner. RESEARCH QUESTIONS THAT DESERVE FURTHER STUDY The literature leaves unanswered the question of what services a dedicated Acute Pain Service should provide and the most cost-effective method in which to provide them. Studies to date have compared a wide variety of staffing models and services to more conventional methods of postoperative pain management. However, no studies have explicitly compared various Acute Pain Service models with each other. In all likelihood, the most cost-effective way to implement an Acute Pain Service will vary among hospitals because of local variations in culture and personnel, for example. In addition, smaller hospitals that perform a range of surgical cases may face more variability in the demand for expert postoperative pain management. This observation is based on the law of large numbers, which states that there is more variability in smaller samples. Such low volume hospitals will need to find ways to manage this variability, such as pooling staff and resources across hospitals. More work also needs to be done to quantify the efficacy of a dedicated Acute Pain Service. A typical outcome considered is some measure of pain scores. The Quality-of-Recovery instrument, for instance, has 9 questions, at least 4 of which pertain to pain or side effects from analgesics.15 However, a challenge for the health economist is that these measures need to be translated into units more easily understood by decision makers. For example, efforts could be made to translate these pain scores to quality-adjusted life years, the measure of efficacy used by many public payers.16 However, the time horizon in acute surgical care studies is typically measured in days and weeks and not months or years as for treatments aimed at relieving chronic conditions. As a result, a dedicated Acute Pain Service may have little effect on the conventional metric of quality-adjusted life years. Therefore, additional efforts should be made to define what measures payers should consider, and present economic analyses in a way that practicing clinicians and payers can understand and translate to their practice. Future studies could also report alternative outcomes of relevance to hospital administrators. For example, a group of pain service interventions increased Press Ganey measurements of patient satisfaction from the 87th to the 99th percentile.17 More understanding is needed regarding which of the several reported interventions had the largest impact. Efforts to date to estimate the efficacy of a dedicated Acute Pain Service have included consideration of the average effect in a study population. However, this approach may obscure the utility of an Acute Pain Service for 2 reasons.18 The first reason concerns differences in patient responses. If a dedicated Acute Pain Service provides a large benefit for a small portion of the population, the average effect will be small, but clearly the Acute Pain Service still has an important clinical role. The second reason concerns dependence in responses across different alternatives to pain management. Put simply, the issue here is whether patients who fail to respond to basic methods of pain management are likely to see large improvement with the expertise of an Acute Pain Service. If an Acute Pain Service is likely to provide large benefits for patients who are not responding to other modalities, the service also has an important clinical role, even if its average effect (measured across a larger population) is small. This latter possibility is particularly relevant in some hospitals where the anesthesiologist-staffed Acute Pain Service typically focuses on particularly difficult cases that have been refractory to more conventional methods. Ultimately, these factors suggest that a dedicated Acute Pain Service can improve its cost-effectiveness by targeting its efforts toward patients most likely to benefit. Unfortunately, our ability to identify these patients remains limited and is another area for further study.19 Finally, in calculating the costs of an Acute Pain Service, the present study focuses on the costs of the service itself, measured as staff time and the costs of administered medications. Personnel costs will differ among countries both in the absolute cost of an anesthesiologist and nurse, and in the relative cost of one to the other. This markedly affects the optimal mix of providers for an Acute Pain Service.20 In addition, these measures of costs are incomplete, because they do not account for the net costs, taking into account the possibility that improved pain management may reduce costs by shortening hospital stay or decreasing the probability of complications. As an example, total knee arthroplasty patients discharged home with a continuous femoral nerve block had reduced hospital length of stay and associated costs and charges, not including postdischarge resource utilization.21 Because stakeholders are likely to be interested in the net costs of running an Acute Pain Service, future studies should investigate how pain management affects total hospitalization and downstream costs. Providing an Acute Pain Service is not solely an anesthesia issue. The hospital facility needs to invest in training, supplies, and policies. In fact, a dedicated Acute Pain Service provides the opportunity for anesthesiologists to extend their influence in perioperative medicine for the millions of inpatients having surgery. The tasks involved align well with the anesthesiologist's existing skill set. However, the wide variety of practice models in the USA and abroad suggests there has not been agreement on how to provide these services in a financially viable way. Given the large number of surgical inpatients, optimizing pain management may yield large savings. The truth is that whether a dedicated Acute Pain Service can be a cost-effective way of managing postoperative pain depends on multiple conditions, such as work culture, surgical case mix, and reimbursement systems.