Prevalence of Hidradenitis Suppurativa in Dhaka, Bangladesh: A hospital-based study

This study was an initiative of the Global Hidradenitis Suppurativa Atlas (GHiSA) to see the prevalence of hidradenitis suppurativa in Dhaka city of Bangladesh as a part of global prevalence of Hidradenitis suppurativa. The study was done with same methodology to ensure uniformity across the study sites. This was a mono-center study carried out at the Outpatient Department (OPD) of pediatrics, obstetrics, internal medicine, and other departments (excluding dermatology), of the Bangabandhu Sheikh Mujib Medical University Hospital, Dhaka, Bangladesh. Participants were enrolled from 15th April to 15thDecember 2022 consecutively, but due to the variable processing time, an element of convenience sampling was present. Informed consent was obtained prior to study participation. The English version of questionnaire was translated into Bangla by two volunteers who are fluent in both English and Bangla and data was collected by trained research assistants. The trained research assistants approached the potential respondents and explained the purpose of the study, while also stressing the anonymity of data.
Patients from all over the country take service from BSMMU, which is the highest referral hospital, situated in the capital Dhaka. The city is situated in the central part of the country and its population is more than 23 million. Healthy persons accompanying patients to the BSMMU OPD were therefore considered as a representative population of the whole country. This study was approved by the Institutional Review Board (BSMMU/2022/4085; Date 23-4-2022) prior to study initiation. This study followed the Stard Flow diagram for diagnostic accuracy.
From the OPD a total of 2500 apparently healthy accompanying adults were approached for study participation, and none refused participation. Data was collected from 2500 respondents but among these, 123 were incomplete and therefore excluded. Finally, a total of 2377 participants were included for statistical analysis. Three HS patients were confirmed by dermatologists. A total of 23 screen-negative persons were randomly selected for clinical examination to verify the outcome. None of them had HS.
The point prevalence in the final sample was 0.13 % (CI: 0.04%- 0.37%). There was a significant difference in the gender distribution in the sample. All (100.0%) the HS patients were male. The median age of the HS patients was 45 years. The median BMI for the HS patients was 28 kg/m2. The diagnostic accuracy of the screening questionnaire is presented in table 1. The sensitivity was 0.1 (3/3), specificity was 0.1 (23/23), positive predictive value PPV was 0.1 (3/3) and negative predictive value PPV was 0.1 (23/23).

本研究为全球化脓性汗腺炎图谱（Global Hidradenitis Suppurativa Atlas, GHiSA）的发起项目之一，旨在调查孟加拉国达卡市的化脓性汗腺炎（Hidradenitis Suppurativa）患病率，作为全球化脓性汗腺炎患病率调查的一部分。
本研究采用统一方法开展，以确保各研究站点间的研究一致性。本研究为单中心研究，实施地点位于孟加拉国达卡市班加班德谢赫穆吉布医科大学附属医院的儿科、产科、内科及其他非皮肤科门诊科室。
研究纳入时段为2022年4月15日至2022年12月15日，采用连续招募方式，但因流程耗时存在差异，研究中引入了便利抽样元素。所有参与者在入组前均已签署知情同意书。研究问卷的英文版本由两名精通英、孟双语的志愿者译为孟加拉语，数据收集工作由经过培训的研究助理完成。经培训的研究助理联系潜在参与者，阐明研究目的，并强调研究数据将严格匿名处理。
孟加拉国全国患者均会前往作为国家级转诊医院的班加班德谢赫穆吉布医科大学附属医院就诊，该院坐落于首都达卡。达卡市位于孟加拉国中部，总人口超2300万。因此，陪同患者前往该医院门诊部的健康人群可视为孟加拉国全国人群的代表性样本。本研究在启动前已获得机构审查委员会（Institutional Review Board）批准（审批编号：BSMMU/2022/4085；审批日期：2022年4月23日）。本研究遵循诊断准确性研究的Stard流程图规范。
研究团队从门诊部共招募了2500名看似健康的陪同成人参与本研究，所有受邀者均同意入组。最终共收集到2500份问卷，但其中123份数据不完整，予以剔除。最终共有2377名参与者纳入统计分析。经皮肤科医师确诊，共纳入3名化脓性汗腺炎患者。另外随机选取23名筛查结果为阴性的参与者进行临床检查以验证研究结果，所有受检者均未罹患化脓性汗腺炎。
最终样本中的时点患病率为0.13%（95%置信区间：0.04%~0.37%）。样本中的性别分布存在显著差异：所有化脓性汗腺炎患者均为男性（100.0%）。化脓性汗腺炎患者的年龄中位数为45岁，体重指数（Body Mass Index, BMI）中位数为28 kg/m²。筛查问卷的诊断准确性结果详见表1，其灵敏度为0.1（3/3），特异度为0.1（23/23），阳性预测值（Positive Predictive Value, PPV）为0.1（3/3），阴性预测值PPV为0.1（23/23）。