The economic burden of low back pain in KwaZulu-Natal, South Africa: a prevalence-based cost-of-illness analysis from the healthcare provider’s perspective
1Discipline of Public Health Medicine, School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa
2Cancer & Infectious Diseases Epidemiology Research Unit (CIDERU), College of Health Sciences, University of KwaZulu-Natal, South Africa
3Department of Women’s and Children’s Health, Karolinska Institute, Stockholm, Sweden
4Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
*Correspondence author: Morris Kahere, Discipline of Public Health, School of Nursing and Public Health, University of KwaZulu-Natal, 2nd Floor George Campbell Building, Mazisi Kunene Road, 4041, Durban, South Africa, Email: mrrskhr@gmail.comABSTRACT
Background
Globally, low back pain (LBP) is associated with high economic costs due to healthcare expenditure and production loss. There is lack of evidence regarding this in low-and-middle-income-countries (LMICs), including South Africa. Thus, the study aimed to determine the economic burden of LBP from the providers perspective.
Methods
We used a retrospective prevalence-based cost-of-illness methodology to estimate the direct medical cost of LBP. Direct medical costs constituted costs associated with healthcare utilisation in inpatient care, outpatient care, investigations, consultations, and cost of auxiliary devices. We used diagnostic-specific data obtained from hospital clinical reports. All identifiable direct medical costs were estimated using a top-down approach for costs associated with healthcare and a bottom-up approach for costs associated with inpatient and outpatient care.
Results
The prevalence of CLBP was 24.3% (95% CI: 23.5 – 25.1). The total annual average direct medical costs associated with LBP was US$5.4 million. Acute LBP and CLBP contributed 17% (US$0.92 million) and 83% (US$4.48 million) of the total annual average direct medical cost, respectively. The per patient total annual average direct medical cost for acute LBP and CLBP were US$99.43 and US$1,516.67, respectively. The total average cost of medication per patient for acute and CLBP were US$82.53 and US$320.31, respectively. Overall, the outpatient care costs contributed the largest share (38.9%, US$2.10 million) of the total average direct medical cost, 54.9% (US$1.15 million) of which was attributed to NSAIDs and only 10% (US$0.21 million) of the total outpatient cost was due to rehabilitation. The total average cost of diagnostic investigations was estimated at US$831,595.40, which formed 15.4% of the average total cost.
Conclusion
The economic burden of LBP is high in South Africa. Majority of costs were attributed to CLBP. Action should be taken to develop culturally validated cost-effective prevention measures to mitigate the burden of LBP.
Article notes
Competing Interest Statement
The authors have declared no competing interest.
Funding Statement
This study was funded by the University of KwaZulu-Natal College of Health Sciences (CHS Scholarship). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Background
Low back pain (LBP) is a global public health problem that occurs in high-income-countries (HICs) and low-and-middle-income countries (LMICs) across all age groups [1]. Despite the technological advancements in diagnosis and the advent of several intervention approaches in the recent years, Low back pain is known to cause significant socio-economic burden to the society [2]. According to the Global Burden of Disease 2017, the years lived with disability (YLD) due to low back pain has increased by 52.7%, from 42.5 million in 1990 to 64.9 million in 2017 [1, 3]. Globally, LBP is now the leading cause of disability [4]. The burden attributed to LBP is predicted to continue increasing, particularly in LMICs where there is limited health coverage and pro-communicable disease control [1]. Great strides should be taken to address this increasing burden and to alleviate the impact it is imposing on health and socio-economic systems. The magnitude of the burden of LBP can be expressed in prevalence, incidence, and cost estimates.
The prevalence and incidence estimate of LBP vary among studies due to differences in definitions of LBP and methodologies used in different studies over time. Additionally, Anema et al reported that these variations are also influenced by the differences in the healthcare seeking behavior, local socio-cultural systems and beliefs around cause and effect [5]. This lack of coherence and homogeneity makes it difficult to compare different studies. However, in the Western world, the point prevalence of low back pain has been reported to be 15-30%, with an estimated 1-month prevalence of 19-43% and a lifetime prevalence of up to 85% [1]. A systematic review by Morris et al investigating the prevalence of low back pain in Africa showed a pooled lifetime, 12-months and point prevalence of low back pain of 47%, 57% and 39% respectively [6]. These high prevalence estimates observed in the western world can be attributed to a great awareness of LBP and the willingness to report symptoms as compared to other parts of the world [1, 7].
About 90% of low back pain cases are not severe and normally resolves within a few days to a few weeks but up to 10% of cases will develop chronic low back pain (CLBP). According to Watson et al (2010) most patients do not get completely healed but will have “flare-ups” against a background of CLBP, meaning that the majority of patients will have recurrent symptoms [8]. Regardless of the small percentage of CLBP sufferers, this group is responsible for the majority of the economic burden incurred [9]. A USA study of insurance claims by Hashemi et al showed that up to 8.8% of low back pain sufferers had symptoms that lasted for a year and accounted for up to 84.7% of the total costs [10]. Similarly, in a study of the UK working population, only 3% of the patients had symptoms lasted for more than three months but contributed to 33% of the benefits paid out during the period of that study [8, 11].
A cross-sectional study by Ekman et al investigating the burden of CLBP in Sweden reported that the total annual direct and indirect cost of CLBP per patient were estimated at US$2 900 and US$16 600 in 2002 prices, respectively [9]. Another cross-sectional Switzerland study by Wieser et al reported the direct costs of CLBP to be €2.3 billion and indirect costs were estimated at €4.1 billion using the human capital approach and €2.2 billion using the friction cost method, representing 2.3% of the total gross domestic production[12]. Walker et al estimated the direct cost of LBP at AU$1.02 billion and indirect cost at AU$8.15 billion among the Australian adults [13]. In the Netherlands, van Tulder et al reported that the total annual direct costs of LBP were estimated at US$367.6 million, while the total annual indirect costs were estimated at US$4.6 billion [14]. Estimates of the economic burden of LBP in the United States, for both direct and indirect costs, range from $84.1 billion to $624.8 billion [2].
The national development plan (NDP) and health policy in South Africa, seek to decrease the prevalence of non-communicable diseases and improve health outcomes. Plans are also underway to implement the national health insurance (NHI) to ensure accessibility to health and promote quality in health. As the leading driver of disability, understanding of the costs associated with CLBP remains critical to inform health care policy decision and subsequently improve management of CLBP. Using patient health records from five hospital this study aims to estimate the economic burden of CLBP among adults (aged ≥ 18 years), by estimating direct medical costs including inpatient- and outpatient care for management of LBP in tertiary care.
Materials and Methods
Study area
This is a prevalence-based cost of illness study conducted in five randomly selected provincial public hospitals in the eThekwini district in KwaZulu-Natal, South Africa. KwaZulu-Natal is an East coastal province with the second largest population in South Africa. The 2019 population and housing census estimated the population of KwaZulu-Natal to be approximately 11.3 million people (19.2% of the total population) [15]. The KZN GDP per capita is estimated at US$10 406, which makes it fall in the low-income category [16]
Study setting
Addington is a district and regional hospital with 471 beds and 2200 professionals. Addington hospital offer a variety of services including inpatient occupational therapy services for disabled patients. Mahatma Gandhi is a 350 bedded hospital offering inpatient and outpatient care services, including inpatient physiotherapy and occupational therapy services for musculoskeletal patients. Prince Mshiyeni is a 1075 bedded hospital located in Umlazi township. Prince Mshiyeni offers both district and regional services and a variety of clinics available within. Hillcrest hospital is a 167 bedded specialised chronic pain patients’ hospital that takes patients who need nursing care. These patients are referred from the hospitals throughout the entire province of KwaZulu-Natal. This hospital also offers outpatient services for chronic medication and rehabilitation. Clairwood is a 275-bedded specialised rehabilitation and convalescent hospital.
Method of costing
From a healthcare provider’s perspective, we employed a prevalence-based method [17] with a bottom-up approach identifying related cost procedures and activities to estimate direct medical costs associated with outpatient and inpatient hospital care for LBP in KZN between 2018-2019 [17]. Patient records from five eThekwini District Hospitals were accessed to determine the number of patients diagnosed with LBP. Low back pain diagnoses classified as per the international classification of diseases (ICD)-10 codes, specifically M40 – M54, M96 and M99 with subclassification codes related to the lumbar spine or lumbosacral spine were included in this study. Codes which did not allow practical delineation of the lumbar spine were excluded [18]. A simple random sampling technique was used to select the participating hospitals namely Addington Hospital, Clairwood Hospital, Hillcrest Hospital, Mahatma Gandhi Memorial Hospital and Prince Mshiyeni Memorial Hospital.
Management of LBP in South Africa
The management of LBP in South Africa follows a referral pattern. With the health care system organised into four hierarchical levels of access, the South African primary health care is comprised of primary health care centres (PHC), community health care centres (CHC), local clinics and general practitioners (GP). The PHC is first step in the provision of health care for LBP patients and can only dispense pain medication. Patients requiring further investigations will be referred to district hospitals where general support in diagnostics (laboratory tests and imaging studies), treatment, care, counselling, and rehabilitation is provided. The treatment of LBP at a district hospital primarily involves prescription of pain medications, mainly non-steroidal anti-inflammatory drugs (diclofenac and celecoxib), opioids (tramadol) and antidepressants (amitriptyline) [19]. Tramadol and a combination of tramadol and diclofenac are the most prescribed medication. Antidepressants are prescribed if a patient presents with symptoms of depression, and they can also be used in combination with NSAIDs and or Tramadol. Physiotherapeutic management involves exercises and stretches, transcutaneous electrical nerve stimulation, ultrasound, and laser therapy. Foot orthotics (insoles) are prescribed if the biomechanics of the foot is suspected as the root of the problem. In emergency cases, invasive procedures can be recommended. The flow of events is depicted in Figure 1.
Costs
We collected all identifiable direct medical costs incurred due to consultations, resource utilisations for inpatient and outpatient care events associated with low back pain diagnosis/special investigations and treatment (including medications, any invasive procedures, rehabilitation, use of any auxiliary devices) [20]. We computed all costs at the 2019 price level and converted from the South African Rand (ZAR) to United States Dollar ($) using the 2019 average exchange rate (US$1 = ZAR 14.45).
Direct medical costs
To estimate the total direct medical costs associated with LBP, we estimated the average cost of each care event documented in the hospital patient records. The average cost for each care component was multiplied by the total corresponding number of patients identified in that component. All cost-generating events were identified and attributed a monetary value based on market or private sources obtained through consultation with senior medical practitioners from private sector (Joint Medical Holdings Ltd).
RESULTS
Participants
A total of 12169 files were retrieved. The prevalence of CLBP was 24.3% (2957/12169). Females represented 55.2% (n=6716) and males 44.8% (n=5453) of the study population, Table 1. The mean ± standard deviation age was 57.6±15.2 years. Notably, young adults (aged 18 – 27 years) represented the smallest percentage of the study population 5.2% (n=636). Whilst a majority of the population were females, the proportion of males were higher in the age category, 58 – 67 (1068 males compared to 1041 females).
Direct medical costs associated with outpatient care of acute low back pain
We performed an age-and-gender stratified costing analysis, Table 2. The estimated average direct medical cost associated with outpatient care for acute low back pain increased with increasing age for both genders, Table 2. The total annual average direct medical costs for acute low back pain were estimated at US$915,948.87 whilst the cost per patient was estimated at US$99.43. The main cost drivers for acute LBP were pain medication consisting of opioids (tramadol) and non-steroidal anti-inflammatory drugs (NSAIDs) mainly diclofenac and celecoxib which accounted for 83% (US$760,294.08) of the total cost, and per patient cost of US$82.53. NSAIDs, opioids and rehabilitation accounted for 68.5% (US$626,939.04), US$68.06 per patient, 14.6% (US$133,355.04), US$14.48 per patient and 5.4% (US$49,138.92), US$5.33 per patient respectively.
Direct medical costs associated with chronic low back pain
The total annual average direct medical cost for chronic low back pain (CLBP) was estimated at US$4,48 million with the costs per patient estimated at an annual average cost of US$1,516.67. The highest average cost per patient was observed among the elderly population in both genders, female (US$2,219.59) and male (US$1,932.33), Table 3. As per the cost variables, inpatient care contributed the highest cost constituting 46.31% (US$2.08 million) of the total annual average costs for CLBP followed by outpatient care 26.5% (US$1.19 million), investigation 18.5% (US$ 831,595.40), specialists 7.2% (US$323,880.63) and auxiliaries 1.4% (US$62,366.84). The main driver of the outpatient costs for CLBP were medication, which contributed 79.6% (US$ 947,184.96) of the total outpatient costs and 21.12% of the total direct medical cost. NSAIDs were responsible for more than half 55.67 (US$527,124.00) of the total medication costs and opioids accounted for 24.3% (US$229,733.28) of the total cost of medication. Males presented with higher costs across the age groups compared female’s counterpart (Figure 2). Additionally, the costs increased with age. The total costs among those aged 18-27 were estimated at US$33,281.37 with the costs more than quadrupling for middle age groups 28 – 37 and 38 – 47 years, Table 5.
Overall estimated cost for LBP
Overall, the total annual direct medical cost for LBP was estimated at US$5.4 million with costs for ALBP and CLBP accounting for 17% (US$0.92 million) and 83% (US$4.48 million) of the total cost, respectively. The per person annual average total direct cost of ALBP and CLBP was estimated at US$99.43 and US$1,516.67 respectively. The average total cost per patient for ALBP and CLBP is shown in Table 6. Outpatient care costs occurred across both ALBP and CLBP recording US$910,357.74 and US$1,190,149.62 respectively. Medication costs were comparable for both ALBP (US$760,294.08) and CLBP (US$947,184.96). Overall, the main cost driver was outpatient care which contributed 38.9% (US$2.10 million) of the total direct medical cost (US$5.4 million).
DISCUSSIONS
From the health care providers’ perspective, this study estimated costs of LBP (ALBP and CLBP), in KwaZulu-Natal, South Africa. The estimated total annual direct medical cost of LBP was US$5.4 million with higher costs for CLBP compared to ALPB. There were more females with ALBP whilst the opposite was observed with CLBP. The argument could be that due to maternal health conditions women are likely to present with ALBP whilst on the other hand this could be reflecting the general health seeking behaviour between females and males. General, evidence on disease pattern and health care seeking behaviour in developing worlds have consistently indicated poor health care seeking behaviour among males compared to females [21, 22], hence males being likely to present with CLBP.
The result of this study concurs with several other studies and shows that the economic burden of LBP in South Africa is comparable to other high-income countries. A systematic review by Maetzel et al reported that, the small proportion of chronic LBP patients accounts for a large fraction of the total costs [23, 24]. This was also consistent with what was reported by Gore et al in their study of the burden of CLBP in the United States [24]. This can be attributed to the fact that acute LBP generally last for a few weeks with little or no intervention. Therefore the cost is mostly associated with pain medication and rehabilitation for a few weeks. Defined by persistent pain and or disability for more the 12 weeks, chronic low back pain is associated with multiple consultations for a long period of time. In some cases special investigations will be required to aid the diagnosis [25]. In line with current evidence, CLBP is associated with significant disability, hence the leading driver of years lived with the disease (YLD) and the sixth in terms of the disability adjusted life years (DALYs) [3, 26, 27], hence more costs. Most studies have focused on developing guidelines for management, thus, there is scarcity of evidence on prevention of LBP [28]. Future research should focus on prevention protocols in order to improve health outcome by mitigating LBP disability and its economic impact.
Outpatient costs had the highest costs, contributing about 38.9% (US$2.10 million) of the total costs. This was expected as outpatient care involves multiple visits for both acute and chronic LBP. This finding concurs with a study done in Netherlands by van Tulder who reported that the outpatient cost were US$2.1 million [14]. Expectedly, inpatient care had the second highest cost of US$2.08 million contributing about 38.5% of the total cost. However, van Tulder et al reported that inpatient costs were higher than outpatient costs. This difference can also be attributed to differences in healthcare service delivery, and differences in study methodologies. Inpatient care includes costs for admission and the various professionals a patient interacts with during the hospital stay [29]. The high costs underscores the need for institution measures to sensitize and educate the public about LBP prevention measures to limit cases of admission which comes with increased consumption of medication and significant disability [29].
Outpatient care costs were presented in both ALBP and CLBP. All cases report at the outpatient for initial management before referrals for admissions or rehabilitations. It was noted that medication was the main cost driver across all the LBP sub-categories (ALBP and CLBP). The most commonly prescribed medication for LBP was NSAIDs. This finding is consistent with what was observed by Hong et al in their cost of illness study in the UK [30]. Consumption of NSAIDS and opioids was noted to be frequent and indicated by the high costs. Due to the non-specific nature of LBP, pain medication is the most common treatment of convenience [25, 31] Interestingly, the costs increased with age. Again, this is because the prevalence of CLBP increases with age and is associated with multiple consultation, and or therapeutic interventions [30].
To our knowledge this is a first study to estimate costs of LBP in South Africa. The findings show the direct medical costs associated with LBP in primary care. Low back pain is a condition that has been reported frequently across population and under reported, yet its progress affect quality of life and can lead to loss of income due to disability and subsequently over consumption of medication [25]. Our findings indicate that LBP is of public health concern and should be prioritised as research has shown that the future predictions of its economic burden are substantial and continue to rise in low-and-middle-income-countries if no counteracting strategies are implemented [25]. As such it is imperative that LBP should form part of public health promotion and prevention messaging.
Whilst our study is presenting critical information on direct medical costs, we would acknowledge that our data was limited to only direct medical costs associated with outpatients, inpatient care, investigations, specialists, and use of auxiliary devices. In addition, results might not be representative at a national level because of the limited number of participating hospitals. However, the presented finds still suggest the need for action/attention toward recognizing LBP as one of the public health conditions needing attention and with great potential to have negative consequences on health resources. Secondly, it is likely that the reported numbers were underestimated. The ICD codes were handwritten, and this might have affected the reading and results in the exclusion of other potential files, therefore, we it is difficult to exclude selection bias.
CONCLUSION
The direct medical expenditure for low back pain in KwaZulu-Natal is high mainly as a consequence of inpatient and outpatient care events. Outpatient care was the main cost driver and was significantly contributed by medication. Chronic LBP was responsible for the majority of costs, though it was represented by a small proportion of cases. The main cost drivers for CLBP was the inpatient care which involved ward admissions, nursing care and terminal care. Acute LBP only contributed a small percentage of the total costs, though it was represented by the majority of cases. The most common form of treatment for LBP was pain medication, of which NSAIDs was the most commonly prescribed medication, which was sometimes given in combination with opioids or antidepressants. Cost effective, culturally validated, context specific guidelines for the prevention of LBP should be developed and implemented. Measures to be taken to ensure practitioners and patients adherence to guidelines. Thus, this is importantfor policy makers, funders, stakeholders and other involved actors to consider the prioritization of LBP research in the South African context to design cost-effective preventive measures. Urgent action should be taken to develop culturally validated guidelines based on local data to improve the future outcome of LBP and mitigate the burden thereof.
Data Availability
All data generated or analyzed during this study will be included in the published article.
Declarations
Ethical considerations
The study was approved by University of KwaZulu-Natal Biomedical Research Ethics Committee (BREC) (Ref No: BREC/00000205/2019) and the KwaZulu-Natal Department of Health Ethics (Ref No: KZ_201909_002). Gatekeeper permissions were sort from participating institutions prior to the commencement of data collection. To guarantee the anonymity of each participant, the names of respondents, their addresses or other identifying information were included in the questionnaires, but rather each participant was assigned a study ID which was only accessed by the researcher. There was no human participation in this study, as it was a retrospective study of hospital health records for low back pain patients who presented to the hospitals between 2018 and 2019, therefore, no participants consent was required.
Consent for publication
Not applicable
Availability of data and materials
All data generated or analysed during this study will be included in the published article.
Competing interests
The authors declare that they have no competing interests.
Funding
This study was funded by the University of KwaZulu-Natal College of Health Sciences (CHS Scholarship).
Acknowledgements
The authors would like to thank the University of KwaZulu-Natal (UKZN) for the provision of resources towards this project and the UKZN CHS Scholarship that was awarded to facilitate the research running costs.