ORIGINAL ARTICLE Inflammatory back pain and associated disease conditions among patients with chronic low back pain in Bangladesh Sabrina YESMIN, 1 Syed Jamil ABDAL, 2 Aminur RAHMAN, 3 Md. Nazrul ISLAM, 4 Alamgir Mustak AHAMMAD, 5 Shamim AHMED, 4 Md. Abu SHAHIN, 4 Minhaj Rahim CHOWDHURY 4 and Syed Atiqul HAQ 4 1 Dr. Sirajul Islam Medical College, 2 Green Life Center for Rheumatic Care & Research, 3 International Center for Diarrheal Disease Research, Bangladesh, 4 Bangabandhu Sheikh Mujib Medical University, Dhaka, and 5 District Hospital, Sherpur, Bangladesh Abstract Aim: Inflammatory back pain (IBP) is the earliest symptom of axial and other forms of spondyloarthritis (SpA). However, there are no published data on prevalence of IBP among patients suffering from chronic low back pain (CLBP) in Bangladesh. In this study, we estimated the prevalence of IBP and the subtypes of SpA in a tertiary hospital in Bangladesh. Methods: This 1 year cross-sectional study was conducted among 240 CLBP patients in a rheumatology outpa- tient clinic. Assessment of Spondyloarthritis International Society classification criteria of IBP and predefined recognized classification criteria were followed to define different subtypes of SpA. Means and standard devia- tions were reported for continuous variables. Descriptive and bi-variate analyses were accordingly performed. Results: Of 240 CLBP patients, 60 (25%) had IBP and 180 (75%) had mechanical back pain (MBP). Among the 60 IBP patients, 52 (86.6%) had predominantly axial SpA (axSpA) and eight (13.4%) had predominantly peripheral spondyloarthritis. In the axSpA group, 49 (94.2%) had radiographic axSpA (rd-axSpA) also known as AS and three (5.8%) had non-radiographic axSpA (nr-axspA). AxSpA patients could be divided into eight (15.35%) with psoriasis, two (3.8%) with reactive arthritis and one patient (1.9%) had arthritis associated with inflammatory bowel disease. Fifty (83.3%) IBP and 73 (40.6%) MBP patients had age at onset of back pain < 40 years. Forty-two (70%) of the IBP and 100 (55.6%) of the MBP patients had normal body mass index. All these differences were statistically significant (P ≤ 0.0001). Conclusions: Inflammatory back pain is common among patients presenting with CLBP. The commonest cause of IBP is AS, followed by PsA and nr-axSpA. Key words: ankylosing spondylitis, classification criteria, inflammatory back pain, prevalence, spondyloarthritis. INTRODUCTION Back pain is a very common problem worldwide. Approximately 80% of the world’s population develops low back pain (LBP) at some point in their adult life. 1 In the Community Oriented Program for the Control of Rheumatic Diseases (COPCORD) studies, the point prevalence estimates of LBP were 11.4, 2 13.1, 3 15.1, 4 23.4, 5 5.1, 6 6.6, 7 4.0, 8 11.6 9 and 1.9 10 in India, China, Indonesia, Iran, Egypt, Bangladesh, Thailand, Malaysia and Pakistan, respectively. In Bangladesh, the preva- lence rates were 18% and 20% in urban and rural com- munities, respectively. 7 Back pain is considered to be chronic when it persists 3 months or more. 11 The prevalence of chronic LBP (CLBP) is in the range of 4– 24% and is responsible for most of the treatment Correspondence: Dr Sabrina Yesmin, Dr. Sirajul Islam Medical College, 12/3 Outer Circular Road, Dhaka-1217, Bangladesh. Email: dr.sabrina37@gmail.com © 2018 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd International Journal of Rheumatic Diseases 2018