title: Symptom Variability and Early Symptom Regression in the MAPP Study: A Prospective Study of Urological Chronic Pelvic Pain Syndrome.
abstract: We examined symptom variability in men and women with urological chronic pelvic pain syndrome. We describe symptom fluctuations as related to early symptom regression and its effect on estimated 1-year symptom change. We also describe a method to quantify patient specific symptom variability.
  
  
  
  Symptoms were assessed biweekly in 424 subjects with urological chronic pelvic pain syndrome during 1 year. To evaluate the impact of early symptom regression subjects were classified as improved, no change or worse according to the rate of change using 1) all data, 2) excluding week 0 and 3) excluding weeks 0 and 2. Patient specific, time varying variability was calculated at each interval using a sliding window approach. Patients were classified as high, medium or low variability at each time and ultimately as high or low variability overall based on the variability for the majority of contacts.
  
  
  
  Prior to excluding early weeks to adjust for early symptom regression 25% to 38% and 5% to 6% of patients were classified as improved and worse, respectively. After adjustment the percent of patients who were improved or worse ranged from 15% to 25% and 6% to 9%, respectively. High and low variability phenotypes were each identified in 25% to 30% of participants.
  
  
  
  Patients with urological chronic pelvic pain syndrome show symptom variability. At study enrollment patients had worse symptoms on average, resulting in a regression effect that influenced the estimated proportion of those who were improved or worse. Prospective studies should include a run-in period to account for regression to the mean and other causes of early symptom regression. Further, symptom variability may be quantified and used to characterize longitudinal symptom profiles of urological chronic pelvic pain syndrome.
authors.affiliation: Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Electronic address: alisaste@mail.med.upenn.edu.
authors.forename: Alisa J
authors.initials: AJ
authors.lastname: Stephens-Shields
authors.affiliation: Department of Urology, University of Michigan, Ann Arbor, Michigan.
authors.forename: J Quentin
authors.initials: JQ
authors.lastname: Clemens
authors.affiliation: Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Thomas
authors.initials: T
authors.lastname: Jemielita
authors.affiliation: Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: John
authors.initials: J
authors.lastname: Farrar
authors.affiliation: Department of Surgery, Washington University, St. Louis, Missouri.
authors.forename: Siobhan
authors.initials: S
authors.lastname: Sutcliffe
authors.affiliation: Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Hou
authors.affiliation: Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: J Richard
authors.initials: JR
authors.lastname: Landis
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D011472:Prostatitis / Q000175:diagnosis*; D063189:Symptom Assessment; D013997:Time Factors
keywords: cystitis; epidemiologic research design; interstitial; pain; prostate; symptom assessment