Investigation Of Clinical Behavior,diagnosis Delay,possible Reasons And Its Effect On The Prognosis In Axial Spondyloarthritis

Part 1 Cross-sectional study of the clinical behavlor of Non-radiographic Axial Spondyloarthritis:a Comparison with Ankylosing SpondylitisObjectives: To compare the clinic behavior of 776 patients with nonradiographic axial spondyloarthritis(nr-ax Sp A) to ankylosing spondylitis(AS).Methods: Data was collected from 400 nr-axSpA patients and 376 AS patients who were diagnosed in the Department of clinical immunology of Xijing hospital from August 2012 to October 2014. A detailed questionnaire,which contains a number of demographic variables, clinical knowledge,medical history and so on, was used.Results: The Age at symptom onset in AS group was younger than the nr-ax Sp A group(19.71±8.69 years vs. 23.32±8.35 years,p=0.004).The disease duration in AS group was longer than the nr-ax Sp A group(118.18±77.84 months vs. 57.35±47.32 months,p<0.001).There were significant differences between these two groups in gender(80.9%male AS patients vs. 62.0% male nr-ax Sp A patients,P=0.005).The C-reactive protein level in AS group was higher than the nr-ax Sp A group(1.85±2.03 mg/dl vs. 1.25±1.95 y mg/dl,p=0.023).Bath ankylosing spondylitis functional index(BASFI) and BASMI Bath ankylosing spondylitis metrology index(BASMI) in nr-ax Sp A group were significant lower than the AS group(P < 0.05).The constituent ratio of patients with juvenile-onset AS was higher than juvenile-onset nr-ax Sp A(33.0% vs. 21.0%,p=0.002).There were 25% AS patients and 22% nr-ax Sp A patients who come to rheumatology department immediately after disease onset. There was no significant difference between two groups.The frist visit department mainly focus on orthopaedics, general medicine, community hospital and private medical institutions. The misdiagnosis incidence of nr-ax Sp A was higher than that of AS(70.8% vs. 57.4%,p<0.05).Most patients were misdiagnosed as arthritis associated with rheumatic,prolapse of lumbar intervertebral disc and lumbar muscle strain.Patients with AS had longer delay in diagnosis when compared to patients with nr-ax Sp A(72.52±70.80 months vs. 31.63±35.09 months,p<0.001).30.4% nr-ax Sp A patients and 19.9% AS patients haven’t seen a doctor for more than 12 months, respectively. and the above two propotion shows statistical significance(P=0.033).Part 2 Diagnosis delay in patients with ankylosing spondylitis: possible reasons and outcomesObjective: To investigate the diagnosis delay, to analyze the possible reasons and identify its effect on the prognosis in ankylosing spondylitis(AS).Methods : Three hundred and senventy-six patients with AS and 400 patients with nr-ax Sp A admitted in the Department of clinical immunology of Xijing hospital were recruited. The patients were diagnosed by rheumatologist according to the Modified New York criteria or Assessment of Spondylo Arthritis international Society(ASAS) axial Sp A classification criteria. A detailed investigator administered questionnaire was used to gather data. Face-to-face interview was conducted to take medical history and some clinical knowledge.Results: Among these 376 AS patients, the ratio of male to famale was 4.22:1, and 88.3% of the patients were HLA-B27 positive. The average age at AS onset was 19.71 years. However, the average Age at the time of correct diagnosis was 25.83±10.22 years. The mean and median delay in diagnosis was 72.52 months and 58.5 months. One hundred and twenty patients(31.9%) were diagnosed with juvenile-onset AS(Jo AS)(first symptoms≤16 years). Patients with JOAS had longer delayed diagnosis time compared to the patients with AOAS(90.48±77.17 months vs. 63.45±58.85 months, P=0.033). Extra-articular involvement was present in 120/376 patients. And the patients with extra-articular involvement had significantly longer delayed diagnosis time compared to those patients without extra-articular involvement(93.04±67.25 months vs. 62.09±66.16 months, P=0.036). Two hundred and sixteen patients were misdiagnosed, the misdiagnosis rate was 57.4%.The mean delayed diagnosis time in the misdiagnosed group was 92.09±74.95 months compared to 46.09±55.41 months in the non-misdiagnosis group, this difference was statistically significant(P=0.001). there were 25% AS patients who go to rheumatology department immediately after disease onset, and the mean delayed diagnosis time was shorter than the patiens going to other department(10.26±5.66 months vs. 93.27±73.84 months,p<0.001). The comparasions of disease related parameters of activity and severity among the early diagnosis group(diagnosis delay less than 5 years:B group),the late diagnosis group(diagnosis delay more than 5 years:C group) and the nr-ax Sp A group(A group)were conducted. BASDAI:A vs. B P=0.370,A vs. C P=0.004 <0.05,B vs. C P=0.001 <0.05;BASDFI:A vs. B P=0.004 <0.05,A vs. C P=0.002 <0.05,B vs. C P=0.031 <0.05;BASDMI:A vs. B <0.001,A vs. C P<0.001,B vs. C P=0.028 <0.05;ASDAS:A vs. B P=0.390,A vs. C P=0.007 <0.05,B vs. C P=0.004 <0.05;CRP:A vs. B P=0.278,A vs. C P=0.009 <0.05,B vs. C P=0.180;The proportion of AS patients with Sacroiliac joint radiological grading in B group Ⅱ was higher than the C group. and The proportion of AS patients with Sacroiliac joint radiological grading Ⅳin B group was lower than the C group.Conclusion:1. The proportion of patiens with nr-ax Sp A and AS who go to rheumatology department immediately after disease onset is lower. Many patients haven’t seen a doctor for a long time.2. The misdiagnosis incidence of nr-axSpA was higher than which of AS. Patients with AS had longer delay in diagnosis when compared to patients with nr-ax Sp A.3. Delayed diagnosis of AS is common in china, the main reasons for which included juvenile age, extra-articular manifestations, misdiagnosis, initial admission department. And delayed diagnosis resulted in significantly worse disease activity and severity of AS.4. There were significant differences between nr-axSpA and AS patiens in the age at symptom onset,the ratio of male to famale,diagnosis delay,disease duration,clinical follow-up,the C-reactive protein level,the proportion of IBP、BASFI、BASMI,and so forth.