STRENGTHS AND LIMITATIONS OF THIS STUDY
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Uses nationally representative data sets covering the whole population of Finland.
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Represents the actual healthcare costs used for the operative treatment of carpal tunnel syndrome and the associated sick leaves.
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Relied on registry data, which limited the ability to directly assess the quality of clinical outcomes and the cost-effectiveness of open carpal tunnel release.
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Expert opinions on routine practices in Finland formed the basis for defining the number and types of healthcare contacts.
Introduction
Carpal tunnel syndrome (CTS), the compression of the median nerve under the transversal ligament at the wrist, is the most common compression neuropathy of the upper extremity.1–4 The prevalence of CTS is approximately 4% in the general population and even higher in specific risk groups.5–7 Between 2007 and 2016 in Finland, the incidence rate of CTS was 197 among women and 105 among men per 100 000 person-years.8 As it is a common condition, the treatment of CTS has a substantial economic impact on the public healthcare system.9–11
Carpal tunnel release (CTR) is the most common surgical procedure performed by hand surgeons, and the number of CTR cases is expected to grow as the population ages.12–14 In England, over 50 000 CTR procedures were carried out in 2011, a number that is predicted to double by 2030.9 In Finland, mild cases are treated by reducing strain on the wrist and night splinting. Surgery is recommended if symptoms persist despite conservative treatment or in cases of severe entrapment neuropathy. Open carpal tunnel release (OCTR) is a prevalent surgical technique in Finland and is considered a safe and effective procedure.15–20
The estimated annual economic burden of CTS from 2005 to 2012 was US$2.7–US$4.8 billion in the Medicare patient population alone. The calculations of disability-adjusted life-years associated with CTS are comparable to those of peptic ulcer disease and cataracts.21 Multiple studies have examined the cost-effectiveness of CTR, usually by comparing the two techniques, OCTR and endoscopic CTR.16–21 Despite financial pressure on health services globally, real-world data on the societal cost burden of CTR are limited.
We aimed to estimate the economic burden of CTR and to explore the cost formation in Finland’s public healthcare system in 2011–2015. This cost description serves as a benchmark for comparing the economic frameworks of various health systems in different health economics contexts.
Methods
Population
Our study population consisted of the entire population of Finland. CTS diagnosis was defined by the International Classification of Diagnoses (ICD) code G56.0, CTS. Patients were also defined as having CTS if they had the ICD-code G56, mononeuropathies of the upper limb, accompanied by the Nordic classification of surgical procedure (NCSP) code ACC51, CTR. All patients with a concomitant diagnosis of ulnar nerve entrapment, G56.2, were excluded.
Study registers
We used data from the Care Register for Health Care, which includes all private and public healthcare providers. It contains patient-level data for research and administrative purposes, including ICD-10 diagnoses and NCSP codes. We obtained permission from The Social Insurance Institution of Finland and the Finnish Institute for Health and Welfare (FIHW) to study and publish from these registries.
From this care register, we acquired the total number of patients with new CTS diagnoses and, from these patients, the total number of patients undergoing surgery in the year of the diagnosis or the following year. Surgery was defined as having a new ACC51 NCSP code (CTR). We also obtained the total amount of euros reimbursed in sick leaves attributable to CTS for these patients during the year of diagnosis and the following year. The Social Insurance Institution of Finland compensates 70% of workers’ average salary after 10 days for up to 300 days. Sick leaves lasting more than 10 days are recorded in the register because the employer pays sick leaves lasting less than 10 days. Pensions or partial sickness allowances were not included in our study.
Costs
We estimated that the average chain of surgical treatment consists of an appointment with a general practitioner, an electroneuromyography (ENMG) test, an appointment with a hand surgeon, day surgery with no overnight stay, a follow-up call from the surgeon and removal of stitches by a nurse in primary healthcare. This was based on expert opinion on routine practice in Finland. The sum of these unit costs and the reimbursed sick leave per patient is the total cost borne by the public sector for surgically treating one patient with incident CTS. The cost of the ENMG test was based on 2015 pricing in the largest public diagnostic centre in Finland and the cost of follow-up calls was based on the 2016 unit price of the musculoskeletal unit of Helsinki University Hospital. Prices were converted to missing years using the healthcare price index. The FIHW provided the remaining unit costs, and we linearly interpolated the prices for the missing years. We obtained the cost of day surgery from the diagnosis-related group (DRG) price for DRG008O (CTR, uncomplicated). The DRG price is the cost of treatment including overheads. We also surveyed the financial departments of all the healthcare districts to validate the DRG prices provided by the FIHW. All costs shown in the results have been converted to 2015 currency using the consumer price index.22
Patient and public involvement
Patients and/or the public were not involved in the design, or conduct, or reporting, or disseminating plans of this research.
Results
Figure 1 shows the number of incident CTS diagnoses by year and the number of surgically treated patients (with surgical code ACC51 during the same or following year). A total of 41 226 patients, over 8000 per year, were diagnosed with CTS in 2011–2015. Of these patients, 26 917 (65%) were women, and 14 309 (35%) were men. The mean age of patients diagnosed with CTS was 55 (SD 15.5).
A bar chart outlining the number of surgically treated and non-surgically treated patients in Finland.
A total of 28 448 (69%) patients underwent surgery. Of these surgically treated patients, 18 837 (66%) were women, and 9611 (34%) were men. Their mean age was 56 (SD 15.3). Over the study period, the proportion of surgically treated CTS patients rose from 63% to 73%.
Figure 2 shows the cost components per surgically treated patient. The average amount of public funds used for diagnosing and surgically treating incident CTS, including reimbursements as sick leaves, was €2759 per patient in 2015 currency. The average direct procedure cost was €1020. We made validation between DRG prices provided by FIHW and survey from healthcare districts with no statistical difference (T-test, p=0.66). This validation survey can be found in online supplemental table 1.
Supplemental material
A bar chart outlining the total cost per patient and the cost components in 2015 euros. ENMG, electroneuromyography.
Figure 3 shows the total cost of all surgically treated patients and the separate costs of treatment and sick leave. An average of 44% of the CTR patients had more than 10 days of sick leave, and the average sick leave lasted 32 days (SD=32.0). The overall reimbursed days of work reached 80 000, with an average total reimbursed cost of five million annually. When the treatment costs were added, the average societal cost burden of CTR was €20 695 370 annually.
A bar chart of the total cost of surgically treated patients in Finland in 2015 euros.
Discussion
The amount of public funds spent on surgically treating one patient with new CTS in 2011–2015 was €2708–€2832. We observed no clear trend in total cost per patient, but the proportion of surgically treated patients rose from 63.14% to 73.09%. The total annual cost of these treatments was between €18 128 420 and €22 569 973.
For comparison, we also estimated the average cost of the surgical treatment chain of ulnar nerve entrapment.23 The average cost of the operative treatment of ulnar nerve entrapment in 2011–2015 in Finland was €3140 per patient, with a total annual societal burden of €3.6 million.
Possible factors contributing to the increased surgical treatment rate may include increased diagnostic and heightened awareness among healthcare professionals and accessibility and preference for day surgery in a procedure room setting. The increase in surgical procedures between 2012 and 2013 in Finland may have been influenced by regulations to monitor and tighten the waiting times for access to care and queuing up for surgery. These regulations are designed to ensure equal opportunities for accessing healthcare across different regions of the country.
Most previously published studies of the cost of CTR are based on populations in the USA, and costs vary greatly depending on surgical technique, anaesthesia modality, procedure setting and location.24–30 A randomised controlled trial was published in 2006, which examined both the direct and indirect costs of CTS treatment strategies in the Netherlands.31 In 1998–2000, the mean cost of patients’ surgery was €2126 and €2111 in the splinting group. The cost of the CTR procedure was only €69.50, which is less than 10% of the cost per patient that we found in our study. A study comparing the direct and indirect costs of CTR in Canada and the USA revealed that CTR is more cost-effective in the USA because waiting times for surgery are so long in Canada.32 A French single-centre cohort study of 66 patients noted significant cost implications for preoperative wait times.33 In this cohort, 19% of patients who underwent CTR involved preoperative time off work, accounting for 13% of total costs. The study further highlighted that reducing surgical waiting times in France could theoretically save nearly €14 million annually. This finding and studies evaluating the cost imposed on society should have a continuation.
Our study’s strength is that the Care Register for Health Care that we used covers the entire Finnish population and is satisfactorily complete and accurate.34 The paid sick leaves of the Finnish healthcare system prevent patients from returning to work prematurely. The results reflect the actual public funds used to pay for the treatment and the associated sick leaves. Additionally, our analyses did not consider the cost impacts attributed to loss of production.
The data included only patients with one CTS diagnosis, meaning that our results do not apply to patients with bilateral operations. Any complications or reoperations were excluded. We also excluded the costs of reimbursed drugs as the typical postoperative regimen is a small amount of non-steroidal anti-inflammatory drugs, for which the reimbursement is under €10. In Finland, opioids are not typically used to treat post-CTR pain.
All sick leave periods lasting less than 10 days are missing from our data, as they are paid by the employer. Sick leaves related to conservative treatment before the surgery were included in our data. Patients who had undergone bilateral surgery during the same year or the year after diagnosis were counted as having undergone only one operation, but any sick leave from the second operation was included.
We used DRG006O as the cost of a typical CTR. It is only used for treatment episodes that do not require an overnight stay. Some patients are monitored in the ward overnight, and the cost associated with this prolonged ward stay is not included in our results.
We were unable to measure the amount of different healthcare contacts in our data. The decision to combine healthcare contacts in addition to the mandatory ENMG test and actual surgery was based on our definition of a typical treatment chain and may be idealistic. Patients may need a second or multiple appointments or follow-up calls with the general practitioner before referral for surgery, as well as additional, potentially costly follow-up appointments with the surgeon. Sick leaves are usually tailored to the patient, and prolonged sick leave may require single or multiple follow-up appointments with a general practitioner or an occupational physician.
In summary, we estimated that the average amount of public funds used in Finland in 2011–2015 to diagnose and surgically treat new CTS was €2759 per patient, making the annual total burden €20.7 million. Despite the shortcomings outlined above, our results give a reasonable estimate of the costs involved on a patient and societal level. Using real-world data provides a foundation for evidence-based policy-making. In the future, more studies are needed to compare different healthcare systems and treatment strategies to optimise patient outcomes and economic efficiency.
Data availability statement
Data may be obtained from a third party and are not publicly available. The research permit granted by the Finnish Institute for Health and Welfare and The Social Insurance Institution of Finland to publish from their records does not allow sharing the data with external parties. Acquiring the same data requires Finndata approval, instructions may be found at https://findata.fi/en/.
Ethics statements
Patient consent for publication
Ethics approval
The study was approved by the Ethics Committee of Northern Ostrobothnia (ETTMK 107/2017). Informed consent was not sought for the present study because this is a register study, and according to Finnish law, no informed consent is mandatory.
This post was originally published on https://bmjopen.bmj.com