Economic aspects of pain therapy

Michael W. Zenz, Michael Tryba

Department of Anaesthesiology, Intensive Care and Pain Therapy
BG-Kliniken Bergmannsheil, Ruhr- University Bochum
Bürkle-de-la-Camp-Platz 1
D 44789 Bochum, Germany

Reprint from: Current Opinion in Anaesthesiology 1996, 9: 430-35

Summary

Economic aspects of acute pain therapy have been mainly investigated in patients with postoperative pain. Evidence increases that in these patients more sophisticated analgesic techniques e.g. regional analgesia, patient controlled analgesia, multimodal analgesia, significantly improve the quality of patient care compared to conventional pain regimens. Increases of personnel costs together with recent cost reductions of PCA pumps now make PCA cost effective. Several recent studies have demonstrated that in specific subgroups improved analgesia in the direct postoperative period prevents from complications and facilitates early discharge from the PACU and ICU and even may reduce hospital stay.

In chronic pain only few data seem to be proven. Inpatient therapy is more expensive than outpatient therapy with similar outcome results. The limited effectiveness of several invasive methods in pain therapy do not justify the high price in any case. Analgesic therapy may differ by a factor of up to 1 : 30 between different opioids. There is a lack of clear investigations focussing on costs related to outcome or pain relief.

Acute pain

Few data exist on the cost-effectiveness of pain therapy in ambulatory patients with acute pain syndromes. Thus, the review on acute pain will focus on patients with postoperative pain. Postoperative pain is the most common form of acute pain. In western countries every year between 5% and 10% of the inhabitants undergo surgery [1]. 50 to 70% of the patients experience severe pain and 20 to 40% experience moderate pain [2]. During the recent decade evidence increases that more sophisticated analgesic techniques e.g. regional analgesia, patient controlled analgesia, multimodal analgesia, significantly improve the quality of patient care compared to conventional pain regimens as on demand intramuscular administration of opioids.

Analysis of cost-effectiveness of postoperative pain management has to consider various dimensions: costs of analgesics, devices and nursing time, duration of stay on the PACU, ICU and in the hospital and postoperative morbidity and mortality.

Costs of analgesics, devices and nursing time

During the early years PCA pumps were expensive with costs in the range of $3 000 to $5 000. Considering only analgesics and devices cost analyses comparing PCA and conventional analgesic regimes revealed additional costs per patient with PCA in the range of $12 to $35 [3, 4 ]. However, although PCA requires time for equipment set-up, several studies demonstrated a significant reduction in overall nursing time in the range of about 30 minutes per patient day [3, 5, 6], when checking of analgesic prescriptions, drug sign-outs, administration and physician calls are considered. These time savings significantly change the cost-benefit ratio resulting in overall cost savings with PCA in the range of $1 to $13 per patient [5, 6]. Recent cost reductions of PCA pumps and increases of personnel costs make PCA even more cost effective.

Patient controlled analgesia can be performed via the intravenous or epidural route (PCEA). With both administration routes quality of analgesia, patient satisfaction, postoperative complications and hospital stay were similar in a homogenous group of patients with radical retropubic prostatectomy [7 ]. Thus, for the majority of patients PCEA may not provide significant benefits compared with intravenous PCA, but significantly increases the costs due to additional costs for the epidural catheter.

PACU and ICU stay

Improved analgesia in the direct postoperative period may prevent from complications and may facilitate early discharge from the PACU or ICU. This has been confirmed in several recent studies [8, 9, 10], although others were unable to demonstrate a sigificant benefit of a specific regime [11, 12 ], even if analgesia was superior [13].

160 patients with general anesthesia and 103 with interscalene block scheduled for ambulatory shoulder arthroscopy were retrospectively analyzed regarding postanesthesia care unit stay, pain, sedation, nausea and vomiting, and unplanned admissions [12 ]. Interscalene block anesthesia resulted in sigificantly fewer unplanned admissions for therapy of pain, sedation, or nausea / vomiting and a mean reduction in PACU time of 30 minutes. A similar reduction of the PACU time was observed in a prospective randomised study of 71 women with laparoscopic sterilization [8], in which the protocol group received intramuscular ketorolac 60 mg and scopolamine 0.25 mg, intravenous metoclopramide 10 mg, and bupivacaine 0.25% with epinephrine at trocar sites and dripped onto the fallopian tubes. The reduction of the PACU time in the protocol group correlated with improved quality of analgesia, and reduced severity of nausea.

A further study [10] in 90 outpatients scheduled for outpatient tubal ligation supports the observation, that improved postoperative analgesia reduces nausea, facilitates ambulation and recovery and reduces unplanned admissions. Patients were randomised to placebo, 5 ml of 2% lidocaine gel on the sterilization clips or 5 ml of 2% lidocaine on the clips and 200 mg ketoprofen i.v. Home readiness was achieved 70 - 90 min sooner in the balanced analgesia group compared to both other groups (p 0.01) and the patients were able to return to normal activity significantly (p 0.01) sooner. Cumulatively 93% in the balanced analgesia group vs 60% in the two other groups had returned to normal activity on the 2nd postoperative day.

However, although personnel costs acount for almost all PACU costs, decreases in PACU time do not necessarily result in cost savings, since the major determinant of PACU costs was the distribution of admissions [14].

In a large prospective study [9] in 452 patients with major abdominal or thoracic cancer surgery all patients were offered intra- and postoperative epidural analgesia (bupivacaine intraoperatively and bupivacaine + morphine postoperatively). A total of 100 patients who refused or in whom catheter placement failed served as the control group and received postoperative PCA. Control patients and epidural patients were similar in demographic and basic clinical data, duration of surgery (about 6 h) and frequency of ICU admission. Duration of mechanical ventilation (0.5 0.2 d vs 1.2 0.3 d) and ICU stay (1.3 0.5 d vs 2.8 0.8 d) were significantly prolonged in the control group. This study is of special interest, because mean pain scores postoperatively were similar in both groups, supporting the hypothesis that spinal analgesia may have advantages beyond analgesia at least in special patient groups. However, before generally accepted, this observation should be confirmed in a large prspective randomised study.

Hospital stay

Hospital stay is the most important single factor influencing total hospital costs. Several ealier studies have demonstrated that the more sophisiticated analgesic techniques as PCA and regional analgesia may result in significant reductions of postoperative hospital stay [5, 15 - 21]. This observation has been confirmed in several recent studies.

In a double-blind study [22 ] 54 patients scheduled for partial colectomy were randomised to either pre- and postoperative epidural morphine, bupivacaine, bupivacaine + morphine or intravenous morphine. Patients randomised to epidural bupivacaine or bupivacaine + morphine fulfilled discharge criteria approximately 1.5 days earlier than both groups with epidural or intravenous morphine (p 0.005). In patients with funnel chest operation [23 ] epidural anesthesia resulted in a significant reduction of mean hospital stay compared with inhalational and intravenous anesthesia (16.7 d vs 21.4 and 21.9 d), mainly due to a reduction of postoperative pulmonary complications.

The above mentioned study in patients with major abdominal or thoracic cancer surgery [9] demonstrated a significant reduction of hospital stay in the epidural group compared with the PCA group (11 3 d vs 17 4 d). The authors also considered the overall hospital costs and calculated savings in the epidural group in the range of $2 500.

In a small series of eight elderly high-risk patients with laparoscopic colonic resection for neoplastic disease [24] effective epidural analgesia allowed early mobilisation and oral nutrition without nausea, vomiting and ileus resulting in a hospital stay of only two days. The same group [25] reported a median hospital stay of only five days after colonic resection in 17 unselected patients receiving combined intraoperative general and epidural anaesthesia, postoperative continuous epidural bupivacaine (0.25%, 4 ml hourly) and morphine (0.2 mg hourly) for 96 hours, and oral paracetamol ( 4 g daily).

Prevention of chronic pain

Obviously the most important aspect of cost-effectiveness of pain therapy would be the prevention of chronic pain. Although recently several studies [26 - 28] have demonstrated that a strategy based on continuous epidural local anaesthetics and opioids reduces the incidence of phantom pain after limb amputation from 60 - 90% to less than 10% no cost-effective analysis has been performed in this group of patients. Nevertheless, considering the significant impairment caused by severe phantom pain the cost-effectiveness of this strategy is obvious.

Chronic pain

A lifetable estimate of the cumulative probability of developing a pain condition indicates that among persons surviving to age 70, 85% are projected to have experienced back pain and 40% headache [29]. A special problem affects cancer patients, of which as many as 70% are expected to die in unrelieved pain [30].

Back pain

Precise figures of direct and indirect costs of back pain are lacking, but estimates indicate costs of more than $50 billion per annum in the USA. 75% of these costs can be attributed to 5% of patients who become disabled from back pain [31]. More exact figures are presented in a recent paper from the Netherlands [32 ]. The total indirect costs were estimated at $4.6 billion, where 67% were related to absenteeism and only $ 367.6 million were direct medical costs.The total expenses on back pain in 1991 were estimated at 1.7% of the gross national product (GNP) [32 ].

Facing these estimates effective treatment of back pain is economically important. A meta-analysis involving a total of 907 patients gave evidence of efficacy of epidural corticosteroids in the treatment of radicular back pain. For longterm pain relief the OR was 1.87 (95% CI 1,31-2,68) [33 ]. Whereas this study does not discuss any economic aspects it is highly important in this respect, as it demonstrates the need and the quality of possible evaluations of different therapy approaches.

Two recent studies, both from USA, have evaluated the costs of back pain care between different provider types. 1 020 episodes of back pain were analysed from the RAND Health Insurance Experiment [34 ]. The mean number of visits per episode was highest in chiropractors being twice that of the next closest provider. Combining the costs of inpatient and outpatient care with the drug cost orthopedists were significantly more costly than all others, whereas general practitioners had the lowest mean total cost. The limitations of this study have been obvious and were discussed by the authors. The data were already more than a decade old and excluded the elderly population. The most important drawback, however, is the lack of any outcome parameter. All that can be concluded is that differences between provides exist, and that they are economically relevant. [34 ].

Carey et al [35 ] investigated the results of primary care physicians, chiropractors, orthopedists, and HMO providers. The median costs per episode were highest in the urban chiropractor group followed by the orthopedists and being lowest in the group of urban primary care providers. At six months results were similar - time to functional recovery, return to work and pain relief but satisfaction was greatest in patients treated by chiropractors.

Significant cost savings were demonstrated in 395 641 patients with musculosceletal pain treated by chiropractors as compared to medical and orthopedic physicians [36]. Similar results were obtained by Meade et al in a study over 3 years with randomised allocation of patients suffering from low back pain. Chiropractic treated patients derive more benefit than those treated by a hospital outpatient program [37 ]. These positive results are in line with other previous studies [38, 39].

However, the above cited papers have a solely somatic approach to back pain, which certainly does not fulfill the whole spectrum of chronic pain and accompanied psychosocial symptoms. Consequently, there is a second queue of scientific work focussing on cognitive-behavioural and multidisciplinary pain management programmes. A cognitive-behavioural approach in 109 chronic pain patients demonstrated that 30% of previously unemployed patients returned to work in the 1st year follow-up-period [40]. However, in the employed group after 1 year of treatment only 20 of 28 working patients were still at work.

In contrast to this British study, an american outcome investigation of 158 patients treated by a multi-disciplinary approach (physician, psychologist, physical therapist, occupational therapist) demonstrated an inadequate response to therapy by recipients of Workers' Compensation. [41].

A meta-analytic review indicated that nonsurgical multidisciplinary pain treatment more than doubles the number of patients returning to work [42]. As spinal disorders are responsible for 75% of all compensation costs [43] this result is highly important for the public. However, the weakness of most treatments is highlighted in the meta-analysis, as only 37 of 171 studies fulfilled the selection criteria of detailed definition of patient work status and documentation of patients employed at follow up [42].

Analgesic therapy

There are only a few papers investigating the costs of analgesic therapy. Goughnour [44] has calculated that, although drug acquisition is more than 5-fold for sustained release morphine as compared to morphine solution, the total costs including staff costs are half as much. 120 mg morphine per day for 30 days would have a total cost of $ 155.40 using controlled-release morphine as compared to morphine solution with total costs of $ 320.40. The highest cost was calculated for subcutaneous morphine with $ 350.40.

Two recent papers are in favour of oral methadone [45, 46]. Gardner-Nix reported of 5 cases in whom she compared the analgesic expenses of different opioids. In all cases oral methadone was the least expensive. She calculated a relation of 1 : 35 for methadone to subcutaneous hydromorphone, 1 : 7 for the relation to oral hydromorphone, 1 : 1.7 to 1 : 4.2 for the relation to oxycodone, and 1 : 2.3 to 1 : 10.7 for the relation to transdermal fentanyl. However, these figures merely give an economic comparison as the quality of life is an even more imprortant factor. E. g. one patient was reported to gain weight and get his impotence resolved by the change to transdermal fentanyl. In a prospective open study Bruera et al [46] switched 37 cancer patients from subcutaneous hydromorphone to custom-made capsules and suppositories of methadone. Pain relief was better with oral methadone and the total costs were devided by 14. The authors conclude that oral methadone would be particularly useful in developing countries. However, caution is advised as methadone might have an extremely long half-life-time in some patients [47].

In any case, taking the total costs (drug, equipment, supplies, staff time) into account oral therapy is cheaper than any form of parenteral therapy [30].

Cancer pain

A thorough comparison of inpatient and outpatient treatment of cancer pain has been presented by Ferris et al [48] investigating the costs of narcotic infusion. The savings per day amounted to Can $ 219.48. This difference holds true above a break-even point of 318 patient days or 6 patients per year. For 2 500 patient days the difference amounts to Can $ 618 528. Regional outpatient narcotic programmes certainly can reduce costs, but the family labor expended to care for the patient at home were not included. Stommel et al [49] have calculated the family costs to be not much lower than the costs of nursing home care. Costs to the families of cancer patients are usually underestimated.

A synopsis of cost issues related to cancer pain management has been presented by Ferrell and Griffith as a report from the cancer pain panel of the Agency for Health Care Policy and Research [30]. They presented a 13-point framework to identify specific cost isssues. Different NSAIDs range from $ 5 to $ 95, and equianalgesic opioids have a 19-fold price difference. Pareneral and spinal analgesics are associated with significant costs. Personnel costs are estimated at about $ 4 000 per month. Surgical and anaesthetic procedures as well as radiation therapy are not documented in cost issues. The failure to treat pain sufficiently can result in significant costs. The authors calculated the cost of hospital admissions for unrelieved pain at more than $ 5 million per year for one institution.

Reimbursement for simple oral analgesics is not provided in any case in contrast to significantly more expensive PCA costs, although the oral route is the first-line route [50], and although it has been accepted that the best method of cancer pain therapy is the least expensive, least invasive, yet most effictive method possible [30]. In summary, the authors conclude that most cost-issues related to pain are supported only by little and insufficient research [30].

Two identical studies on radiopharmaceutical therapy for the palliation of pain in osseous metastases were presented in 1994 [51, 52]. Strontium 89 therapy resulted in lifetime reduction of Can $ 1 720 per patient when compared with placebo. Robinson et al [53] analysed the literature on Strontium 89 and concluded that 80% of patients with osteoblastic metastases experience pain relief and a minimum of 10% become pain free [53]. Based on the data of McEwan et al and a control by McGowan [54] significant cost savings can be expected by this therapy also compared to local radiotherapy [55].

Invasive therapy

Spinal cord stimulation (SCS) has been analysed for chronic low back pain [56]. Thirtynine studies have demonstrated pain relief of 50% in 59% of patients and complications occurred in 42%. Facing the complete lack of randomised studies, the costs of the system and operation ( > $ 5000), and the ratio of success and complications it is hard to conclude whether patients do not better with the cheaper approaches to pain relief after failed back surgery.

Another indication for SCS is lower limb ischaemia. Here SCS has proven efficacy in a randomised controlled study. Tissue loss was less (p=0.05) in the SCS group. [57]. Similar results can be obtained with a cheaper method - neurolytic sympathetic blockade [58].

Intraspinal opioids have been investigated in the treatment of neuropathic pain [59]. Three of 18 patients had no oral opioid prior to the spinal catheter. The pain score decreased from 8.1 0.3 to 5.8 0.6 in the mean. 5 of 11 successful treated patients continued to use systemic opioids. Six of 18 patients had no long-term pain relief, 16 operative revisions had to be performed in 18 patients. Overall, the cost of initial catheter placement - about $ 12 000 [60] -, the limited results, the high revision rate, and the poor outcome parameter do not justify to regard intraspinal opioids in non-cancer pain as cost-effective.

Also nerve blocks resulted in disappointing effectiveness in different pain states [61 ]. Only 6 of 45 patients had pain relief for longer than 1 month. It was concluded that nerve blocks may only be justified in patients where repeated procedures provide reproductive periods of pain relief of at least one month.

Conclusion

Chronic pain can be a major financial burden for the individual patient. More than $ 1 000 per year of their personal funds spent pain patients on health care [62]. Inpatient and outpatient pain treatment has significant cost-benefit advantages compared to a control group and can substantially contribute to rehabilitation [63].

But there are no studies comparing the costs of different pain treatment methods per unit pain relief, e. g. as cost per unit AUC of a pain score. This would be essential as both the costs and the effectiveness of most methods differ widely. Another essential point relates to the different availability of analgesics due to different cost relations in industrialized or developing countries. The WHO has repeatedly pointed out that many analgesics are not available or not payable in some developing countries. The profit in western countries should pay the needs for pain relief in developing countries. An international initiative of all pharmaceutical manufacturers could guarantee for this neglected demand.

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