Predicting postherpetic neuralgia in elderly primary care patients with herpes zoster: prospective prognostic study.
Postherpetic neuralgia (PHN) is the most frequent complication of herpes zoster (HZ) and difficult to treat. Timely identification of high-risk HZ-patients enables physicians to focus on PHN prevention. To assess which simple to measure factors are independent predictors of PHN, and whether psychosocial and serological/virological parameters have additional predictive value, a prospective cohort study in primary care was conducted. We included 598 elderly (>50 years) consecutive patients with acute HZ (rash <7 days) below sixth cervical dermatome. At baseline demographic, clinical (e.g., duration and severity of pain and rash), psychological (Pain Cognition List [PCL] and Spielberger's Anxiety Inventory), serological (VZV-antibodies) and virological (viremia presence) variables were measured. Blood tests were performed in a random subset of 218 patients. Primary outcome was significant pain (VAS >30 on 0-100 scale) after three months. The final prediction model obtained from multivariable logistic regression was (internally) validated using bootstrapping techniques, and adjusted for optimism. Forty-six (7.7%) patients developed PHN. Independent predictors were age (odds ratio [OR]=1.08 per year), acute pain severity (OR=1.02 per unit), presence of severe rash (OR=2.31), and rash duration before consultation (OR=0.78 per day): area under receiver-operating-characteristic curve [ROC area]=0.77 (95% CI: 0.71-0.82). Of the five PCL scores, only factor V ('trust in healthcare') was an additional predictor (OR=1.01 per unit), though it increased the ROC area with only 0.01 to 0.78. The Spielberger's anxiety scores and serological and virological variables were no additional predictors. Thus, four simple variables can help physicians to timely identify elderly HZ-patients at risk of PHN.
Opstelten
Wim
W
Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, P.O. Box 85060, 3500 AB Utrecht, The Netherlands Eijkman Winkler Institute for Microbiology, Inflammation and Infectious Diseases, University Medical Center Utrecht, The Netherlands Pain Clinic, Department of Anaesthesiology, Division Perioperative Care and Emergency Medicine, University Medical Center Utrecht, The Netherlands.
Zuithoff
Nicolaas P A
NPA
van Essen
Gerrit A
GA
van Loon
Anton M
AM
van Wijck
Albert J M
AJM
Kalkman
Cornelis J
CJ
Verheij
Theo J M
TJM
Moons
Karel G M
KGM
D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology*; D000914:Antibodies, Viral / Q000097:blood; D015331:Cohort Studies; D018450:Disease Progression; D005076:Exanthema / Q000175:diagnosis / Q000821:virology; D005260:Female; D006562:Herpes Zoster / Q000150:complications* / Q000503:physiopathology; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D051474:Neuralgia, Postherpetic / Q000175:diagnosis* / Q000523:psychology / Q000821:virology*; D009483:Neuropsychological Tests; D010147:Pain Measurement; D017288:Pain Threshold / Q000523:psychology; D011237:Predictive Value of Tests; D011320:Primary Health Care / Q000706:statistics & numerical data*; D011379:Prognosis; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D019562:Viral Load
D000914:Antibodies, Viral