Table of Contents
A facility-based cross-sectional study design was conducted at a referral hospital in Amhara Region from May 1 to 30, 2022. Amhara Region is one of the 12 regional states in Ethiopia. According to the Ethiopian Fiscal Year Report 2020, the region has an overall population projection of 22,191,890 (11,317,864 males and 10,874,026 females).12According to the Amhara National Regional Health Authority’s annual performance report, there are 81 hospitals in the region, including eight referral hospitals at the University of Gondar (UoG), Desie, Fereghe Hiwot, Tibebe Gion, Debre Markos, Woldia, Debre Tabor and Debre Birhan.12All these referral hospitals serve the local population and provide multifaceted care to patients who require medical services including surgery, internal medicine, paediatrics, maternity and other services.These hospitals also have specialised units and clinics such as diabetes mellitus (DM), antiretroviral therapy (ART) care and support services, cardiology, respiratory, nephrology, neurology, dermatology, sexually transmitted diseases, intensive care units and many other services.
From the total number of referral hospitals, four hospitals were randomly selected: Debre Tabor Referral Hospital, Dessie Referral Hospital, Tibebe Ghion General Referral Hospital, and Debre Markos Referral Hospital. These hospitals saw approximately 2,064 type 2 diabetes patients every month.
The study and study population included adult type 2 diabetes patients undergoing follow-up care at referral hospitals in Amhara region and randomly selected patients between 1st and 30th May 2022.
All adult patients with type 2 DM receiving follow-up care at the selected hospitals from May 1 to 30, 2022 were included. However, patients with type 2 DM with leprosy or peripheral nerve damage were excluded.
The sample size was determined using the single population proportion formula, taking into account: 95% confidence interval (CI), 0.536 population proportion from the previous study13and a margin of error of 5%. N =[(Zα/2)2*p(1−p)]/(day)2where n is the initial sample size, Z α/2 is a standardized normally distributed value with 95% CI 1.96, P is the proportion of peripheral neuropathy, and d is the margin of error of 5%. By adding a non-response rate of 10% and a design effect of 1.5, a final sample of 627 type 2 diabetes patients with ongoing follow-up was included.
Four hospitals were randomly selected and then proportionally allocated to each referral hospital.A systematic random sampling method (k = 3) was employed to select study participants (Figure 1).
Summary sampling procedure for the prevalence and associated factors of peripheral neuropathy among adult type 2 diabetes patients attending a referral hospital in Amhara region in 2022 (n = 627).
The first participants from each referring hospital were selected by lottery, and for the selected participants, medical records were obtained from the medical record room and a face-to-face interview was conducted in a convenient private room.
The outcome variable was DPN, assessed using the Michigan Neuropathy Screening Inspection (MNSI).14The MNSI consists of two steps. The first step of the MNSI is a medical history questionnaire that evaluates the presence of neuropathic symptoms. This part consists of 15 items, of which 13 items evaluate symptoms of DPN. Item number 4 is a scale of circulatory disorders, and item number 10 is a scale of general asthenia and was not included in the scoring. A “yes” answer to items 1-3, 5-6, 8-9, 11-12, and 14-15 is counted as 1 point each. A “no” answer to items 7 and 13 is counted as 1 point. The score range is 0-13, and a score of 7 or more indicates the presence of neuropathic symptoms.
The second step of the MNSI is the physical examination portion, which is scored from 0 to 5 points. The physical examination included examining the appearance of the foot for deformities, dry skin, calluses, and infections, checking for the presence of ulcers, testing the 128 Hz vibration sensation with a tuning fork, using a hammer to detect the ankle reflex to detect the quality of stretch reflex pathway function, and performing a monofilament test. A Chinese-made 5.07/10g monofilament was used to detect loss of pressure sensation in the foot. This is an objective instrument used in screening diabetic patients for loss of protective sensation in the foot. To avoid diagnostic errors, 10 patients were tested using each monofilament. Participants with their eyes closed were asked to answer “yes” if they felt the filament. Nine sites on the bottom of the foot and one site on the top of the foot were tested. If 8 out of 10 applications were correct, they were considered normal and received a score of 0. One to seven correct responses indicated reduced sensation and were scored 0.5, whereas no correct responses were interpreted as no sensation and were scored 1.
Finally, patients were considered to have DPN if they had an abnormal response Michigan Neuropathy Screening Examination (MNSI) questionnaire score of 7 or more on the medical history version and an MNSI score of 2.5 or more on the leg and/or lower extremity examination version.
Nineteen variables were used as independent (covariate) variables: socio-demographic (age, sex, place of residence, marital status, family structure, residential status, educational status, occupational status, wealth index, and family history of DM), behavioral factors (alcohol intake, smoking, khat chewing, and physical exercise), and clinical factors (FBS (fasting blood glucose) (mg/dl), treatment regimen, BMI (body mass index) (kg/m2), abdominal circumference (cm), presence or absence of complications, etc.
The Wealth Index is an asset-based index of a household's material well-being or economic status that can be used in all low- and middle-income countries.15The study had 14 and 26 questions to measure the wealth levels of urban and rural residents, respectively. All categorical variables were labeled as 1 and 0. Similarly, continuous variables were categorized between 0 and 1.
For behavioral factors, alcohol, khat, and tobacco smoking, participants who had used psychostimulants such as alcohol, khat, or tobacco at least once within the past 30 days were classified as current users.16.
Patients were considered physically active if they engaged in at least 150 minutes of moderate-to-vigorous physical activity per week.13,17.
In this study, comorbidity was defined as the presence of one or more chronic diseases in diabetic patients and could be classified as concordant or incongruent comorbidity.18Waist circumference (WC) measurements were as follows: Adults aged 20 years and older were classified into three health risk categories according to cutoffs recommended by the WHO and the National Institutes of Health (NIH).17.
Data were collected through a structured questionnaire, the MNSI, a standard height scale, and a weight scale. The MNSI is a well-known instrument used to assess peripheral neuropathy in patients with DM, with a sensitivity of 80% and a specificity of 95%.14,19Some questionnaires were adapted by reviewing different literature such as wealth index and socio-demographic questionnaires.15,20The English version of the questionnaire was translated into the local language (Amharic) and then translated back into English by a language expert.
Anthropometric measurements were performed to determine the height and weight of study participants. Weight was measured on a calibrated scale while lightly clothed. Height was measured on a scale while standing upright on a flat surface. BMI was calculated as kg/m.2 Data collection was conducted through face-to-face interviews to determine nutritional status of body composition, as well as review of patient records and physical examinations.
Four data collectors with experience in data collection and four MSc nurses as supervisors were recruited for data collection. The data collectors, including the supervisors, underwent training together for two days. During the training, the importance of obtaining verbal consent from respondents and respecting their right to answer or not answer any part of the questions, as well as ensuring privacy and confidentiality, was emphasized. After the supervisors and data collectors were assured of the clarity and completeness of the questionnaire, they received a data collection format in which the details of each question were clarified to ensure a uniform understanding of the meaning of each question.
To assess the relevance of the questions, a pre-test was conducted at the Diabetes Clinic of the University of Gondar Multispecialty Hospital with 5% of the sample population. Consistency, accuracy and internal consistency were checked, with a Cronbach's alpha of 0.75. The collected data were checked daily for accuracy and completeness by the principal investigator and a supervisor.
Data were coded and checked for completeness and consistency, then entered into Epi-Data version 4.6 and exported to SPSS version 25 for analysis.
Binary logistic regression models were fitted to examine the association between each factor and the outcome variable. p Values less than 0.25 were included in a multivariate logistic regression model to adjust for confounding effects. Finally, 95% confidence intervals and p Values less than 0.05 were used to report factors independently associated with DPN.Model fit was checked with Hosmer and Lemeshow goodness-of-fit test, with a significance level of 0.861.
The study was approved by the Research Ethics Review Committee of the Faculty of Nursing, Faculty of Medicine and Health Sciences, on behalf of the University of Gondar Review Board (reference number S/N0042/22). The Research Ethics Review Committee of the Faculty of Nursing accepted and approved that the study was conducted in accordance with the relevant guidelines/regulations, the Declaration of Helsinki, and oral/informed consent approval. Formal letters indicating approval were obtained and submitted to all four referral hospitals and the Amhara Regional Health Directorate.
Verbal consent/informed consent was obtained from each participant for participating in the interview and physical examination. Confidentiality was maintained at every step. Finally, after the entire process of data collection, the questionnaires were kept secure throughout the entire process of the research work.