Study design
A cross-sectional survey design was carried out on adult T2DM patients diagnosed with DPN. This design conducted at a period starting from 15th of June 2019 to the 5th of October 2019.
Setting
The study was conducted at the Jordanian Ministry of Health. The three hospitals are integrated under the name of the Jordan Ministry of Health. The researcher chose this setting because it receives referrals from all medical sectors in different parts of Jordan. It will be assumed that the selected setting would have a reflection of a patient with diabetes from different parts of Jordan. This center was established in 1921 Amman, Jordan with an annual admission rate of 25,000 patients of all disease that provides services to all patients from all around Jordan. Also, that provides screening services for each patient attending the Jordanian Ministry of Health center (clinics or hospitals), the services include following up of patients with diabetes mellitus every three months, in addition to routine measurements of blood glucose HbA1c, blood pressure, weight, height, and waist circumference that are carried out in each visit. Every day, the medical records staff in each clinic picked up all the medical files of patients. They made them available on the nursing desk. Once the patients show up, they were received by a qualified nurse who performs some physical examinations that are needed for them before seeing their treating physician. Also, there are several specialized clinics in the center to deal with the complications of diabetes.
Sampling And Sample Size
The target population for this study was all adult T2DM patients with DPN who visited the Jordanian Ministry of Health, during the period from the 15th of June 2019 to the 5th of October 2019, and who are ≥ 18 years of age having regular follow up in the hospitals for at least six months were included in the study.
Patients with the following conditions were excluded from the study as T1DM because those patients are beyond the purpose of this study. Besides, adult patients who underwent amputation of the whole foot, below the knee and above-knee amputations, were also excluded from the study because of the limited possibility to perform a physical examination on those patients. Also, the study does not examine any patient who didn’t give verbal consent or respond to the questionnaire. The total sample size was 400 T2DM adult patients with DPN.
Study Instrument
An assessment tool package was used. This package consists of four parts. The first part was developed by the researchers and consisted of the demographic data, anthropometric measurement (last reading), laboratory measurement (last reading), type of treatment and type of diabetes that was obtained from the subjects who met the inclusion criteria.
The second part is an interview questionnaire Douleur Neuropathique4 DN4 (Bouhassira et al. 2005), the questioner diagnosis of DPNP among adult T2DM patients with DPN was made by a score of ≥ 3. The DN4 score was derived by counting the number of positive responses to each of the first 7 items of the questionnaire, which includes burning sensation, painful cold sensation, electric shocks, tingling, pins and needles, numbness, itching, hypoesthesia to touch, hypoesthesia to prick, and brushing [16]. Only those who completed all 10 items of the DN4 questionnaire were included in the analysis for estimating the prevalence of DPNP, the responses to the questionnaire were either Yes or No. Also, Scores ≥ 3 a sensitivity 89.9% were used in identifying patients with DPNP among adult T2DM patients with DPN while using a cut-off score point of 3 items out of 7 has a sensitivity 78% and specificity of 81.2% in identifying patients with DPNP [16]. This questionnaire was reported by the International Association for the Study of Pain in 2004 by (Bouhassira). The analysis of the psychometric properties of the DN4 questionnaire included: face validity, factor analysis and logistic regression to identify the discriminate properties of items or combinations of items for the diagnosis of neuropathic pain. The Arabian reliability and validity studies of the DN4 questionnaire was performed by Terkawi, A. S. et.al. in 2017, the results showed Arabic DN4 to have good diagnostic accuracy, with an area under the curve of 0.88. As with the original version, a score of ≥ 4 was found to be the best cut-off for the diagnosis of DPN, with a sensitivity of 88.31%, the specificity of 74.47%, a positive predictive value of 85%, and a negative predictive value of 80%. The Cronbach’s alpha of the revised scale was 0.67 [17].
The third part is a physical exam; this is the second section from the DN4 questioner it includes hypoesthesia to touch, hypoesthesia to prick, and brushing [16]. The researcher was filled in each questionnaire using face to face interviews in the Arabic language.
The fourth part is the quality of life questionnaire entitled EQ-5D [18]. This standardized instrument includes four domains that measure the QoL: mobility, self-care, usual activities, and anxiety/depression. The overall score was as 1: perfect health and 0: dead [18]. The EQ-5D has been translated by the researcher and checked by two professional academic instructors (Dr. Maysoon Abdalrahim and Dr. Ruqayya Zeilani) in the field of nursing to ensure the consistency of inquiring the information while interviewing the patients. The Jordanian reliability and validity studies of the EQ-5D was performed by Jawad Ahmad Abu-Shennar et.al. in 2020. The Cronbach’s alpha of the revised scale was 0.88 [19].
In addition to the above measurements, the researcher measured the intensity of pain using the Numeric Pain Rating Scale (NRS). Each patient was asked to point to the number that represents the intensity of his current pain experience.
Data Collection
Data were collected with the following stages:
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Early on the day of the visit to the hospitals, excluding weekends (Fridays), the researcher made a list of adult T2DM participants’ names with DPN and file numbers of those who meet the criteria of enrollment in the study.
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A face-to-face structured interview was made with the adult T2DM patients with DPN while waiting for his turn with the treating physician after finishing their laboratory check and nursing examination. Descriptive data were obtained and Douleur Neuropathique4 DN4 was implemented to evaluate DPNP. Each interview lasts for about 10 to15 minutes.
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After the interviews, a physical examination for each participant was performed using the second section from the DN4 for evaluation of DPNP and patients with DPNP were determined.
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The intensity of pain was measured using the Numeric Pain Rating Scale (NRS) among the DPNP patients.
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Finally, the quality of life questionnaire entitled EQ-5D was collected among patients having DPNP.
Statistical analysis
Statistical analysis was carried out using the Statistical Package for Social Sciences (SPSS, version 25). Descriptive statistics obtained such as mean and stander deviation values for continuous and proportions for categorical variables. Chi-square was used to test the independent distribution of categorical variables where appropriate. Binary logistic regressions were used to examine the net effect for each of the proposed variables on DPNP. A P-value of less than 0.05 considered statistically significant.
Ethical Consideration
Data were collected after approval by the ethical committee in the Jordanian Ministry of Health. We have got approval from consultant specialist neurologist to apply of the DN4 as required of the Jordanian Ministry of Health ethical committee. The data was used only for scientific inquiries. Since the study was based on data obtained from medical records and structured questionnaires, no harm to the adult patients (T2DM) with DPN was expected. Verbal consent was taken by those eligible participate and they were assured about the confidentiality of information.