Modelling Outpatients Cost of Wound Dressing in Nigeria: A Prospective Study

Background: Estimating the direct cost of wound dressing poses a challenge to patients, nurse managers, hospital administrators, health maintenance organisations and other policy makers. This study therefore model the weekly cost of wound dressing in South West Nigeria Methods: A descriptive cross sectional research design was utilized to assess the cost of wound dressing among outpatients’ clinics attendees. An inventory of direct cost of wound dressing per week consisting of cost of materials, lotion and consumables were recorded. The data collection was for period of three months in three selected Teaching Hospitals South West Nigeria. Then modelling weekly cost of wound types was done by regression analysis. The effect of various independent variables such as age, occupation, family size, monthly income, aetiology, diagnosis, wound type, comorbidities, frequency of wound dressing and health insurance coverage on cost of wound dressing per week was considered. Ethical approval was obtained from each of the hospital and Covid-19 precautions were observed.1 USD Results: The estimated cost of wound dressing per week with no contribution from other variables was found to be ₦36,922- Open wound, ₦6011-Leg ulcer, ₦3768- Cancer wound, ₦2785- Diabetic Foot Ulcer, ₦610-Surgical wound. Only frequency of wound dressing was found to contribute to weekly cost of leg ulcers (P value= 0.003) Conclusions: The estimated cost of various type of wound provides yardstick for determining the weekly cost of wound dressing in Nigeria. Also, frequency of wound dressing is a major determinant of the outpatient cost of dressing. Therefore, it is imperative for nurses to render high quality wound care to match up with the huge nancial commitment from patients and families


Introduction
Wound dressing is an integral part of wound care protocol and it is known to consume huge healthcare resources [1,2] . The geometric rise in the cost of wound care has received the attention of many wound care researchers [1,[3][4][5][6] . However, the gap in most studies is how to determine the cost implications for successful wound dressing. Critically, wound dressing cost allocation poses challenge in terms of wound aetiology, diagnosis, wound type, choice of dressing materials and frequency of wound dressing [2] One suggestion is to compute the cost of wound dressing in relation to each wound type. Studies which model the weekly cost expectation of wound dressing are sparse. Healthcare policy formulation, care protocol and service charges are undermined due to inappropriate wound dressing accounting system.
Often, cost of wound dressing are subsumed into surgical procedural bill [1,2,7] , therefore, a nursing care friendly accounting system is require to estimate the cost required for successful wound dressing [7,8] According to Ogundeji et al [1] , the cost of continual wound dressing alone constitutes fty percent of the wound care cost. Furthermore, it is worth noting that, in most part of Africa, a prospective guideline for wound dressing coverage and costing is lacking [1,2,7,8] . It follows that wound dressing assessment and pricing is arbitrary. This signi cantly causes a hitch for health maintenance organisations, hospital administrators, nurse managers and other policy makers in the cohort. The authors are also concern with inordinate computation of wound dressing billing by hospital administrators and health personnel. Patients are likely to pay less or more.
From experience, cost of wound dressing is allocated as board and room rate irrespective of wound aetiology, diagnosis and type. A recent eld report on wound dressing among outpatients' attendees in some Teaching Hospitals in Nigeria revealed that cost of wound dressing is a xed price with great variations among the hospitals [8] . Furthermore, extant studies underlined that cost determination without consideration for patients' characteristics assumed that all patients use the same nursing resources [7][8][9][10] . Dyke, Wantland, Lipsitz & Saba [11] and Rutherford [10] posited that nursing care will become an important hospital generating unit if nurses can articulate a scienti c costing model for various nursing skills.
Moreover, wound dressing requires much of nursing intensity and it is a major cost drive among surgical patients [1,2,12] . Following plethora of evidences surrounding the frequency and cost of wound dressing in Nigeria, the authors model the weekly cost of wound dressing among outpatients using a regression model. This is imperative to provide data for the basis of designing a wound dressing tariff in Nigeria Teaching Hospitals. The outcome will also foster policy making and operational guidelines on wound dressing in Nigeria and West Africa sub-Region

Study design and settings
A descriptive cross sectional research design was followed to assess the cost of wound dressing among patients visiting the medical and surgical outpatients' clinics of the three selected tertiary hospitals in South West Nigeria. This was followed by regression model analysis to model the weekly cost of different type of wounds. The unit cost of varied type of wound was computed with consideration for dependent and independent variables. The in uence of independent variables such as age, occupations, family size, monthly income, wound aetiology, diagnosis, wound type, comorbidities, frequency of wound dressing and enrolment into health insurance scheme on the cost of wound dressing per week (dependent variable) was considered. Furthermore, a mathematical model was included in the analysis for predicting the future cost of wound dressing in Nigeria.
The patients were asked to give an inventory of direct cost of wound dressing per week detailing the cost of dressing materials, lotion used and consumables excluding the professional charge. The cost estimation was recorded in Nigeria currency (Naira=₦), 1 USD equalled ₦570. The data was collected every week for a period of three months in three Nigerian Teaching Hospitals. The inclusion criteria were adult patients with wounds who are regular Outpatient' clinics visitors for a period not less than four weeks. The drafted research proposal was reviewed and approved by the University of South Africa College of Human Science Ethical Committee with reference number 2020-CHS-90163346.
Ethical Clearance was also obtained from the Institutional Review Board (IRB) of the selected hospitals which include the National Orthopaedic Hospital Igbobi Lagos (OH/90/C/IX), the University College Hospital Ibadan (NHREC/05/01/2008a-21/0047) and the Obafemi Awolowo University Teaching Hospital Complex, Ile-Ife (ERC/2021/04/07). Also, verbal and written consent was received from each participant while ethical principles of anonymity, voluntariness and con dentiality were upheld. Furthermore, data collection was conducted during covid-19 pandemic, therefore, safety precautions as regards hand washing, physical distancing and face masking were strictly observed Results And Discussion Of Findings: Parameter estimates of cost of wound dressing   and Dumville [13] which associated high cost of wound dressing to repeated dressing changes.
Moreover, our estimate corroborates similar ndings by Lotz [14] and Brain, Tulleners, Lee, Cheng, Graves, Pacella [15] that choice of wound dressing materials and the procurement cost are factors modulating the frequency and cost of wound dressing per week. Patients can make choice of traditional or modern dressing materials. Typically, modern dressing materials are advocated to improve wound care and rate of recovery but with increased cost of procurement. This is also in uenced by the exchange rate as modern dressing materials are imported from high income countries to Africa.

Again, the regression analysis also support the perspective by Builders & Oseni-Momodu [16] and
Odhiambo, Omondi & Magak [17] that frequency of wound dressing means increase use of dressing materials per week with the associated cost. This nding particularly has implication for nurses' quality wound assessment and care. Interestingly, wound care nurses are conspicuously lacking across care settings in Nigeria. To the best of researchers' knowledge, there is no certi cation and licensure wound care training programme for nurses in Nigeria. This development was also reported by Ogundeji et al [1] and Ilesanmi & Ogundeji [2] . Currently in Nigeria and in most part of sub-Sahara Africa, wound dressing is left at the jurisdiction of all categories of nurses  KD and PR conceived the study. KD and GB source for study materials. KD analysed data and wrote the rst draft of the manuscript.PR and GB review the manuscript for intellectual content and suitability for publication. The nal version of the manuscript was read and approved by all authors