title: Folic Acid Supplementation Is Suboptimal in a National Cohort of Older Veterans Receiving Low Dose Oral Methotrexate.
abstract: OBJECTIVE
  Co-prescription of folic acid in patients receiving low dose oral methotrexate is recommended because it reduces adverse events and prolongs the use of methotrexate (MTX). However, little is known about how often new users of methotrexate are co-prescribed folic acid, and what factors are associated with its use. We aimed to determine the prevalence, predictors of, and persistence of folic acid use in a population-based cohort of MTX users with rheumatic diseases.
  
  
  METHODS
  Using a national, administrative database of patients seen through the Veterans Health Administration (VHA) that included pharmacy and laboratory data, we performed an observational cohort study of veterans over 65 years old who were new users of MTX. We used log-binomial regression to identify independent predictors of folic acid use and Kaplan Meyer survival analysis to examine persistence of folic acid over time.
  
  
  RESULTS
  We studied 2467 incident users of MTX. 27% of patients were not prescribed folic acid through the VHA pharmacy within 30 days of MTX initiation. Patients who did not see a rheumatologist were 23% less likely to receive folic acid compared to patients who did have a rheumatologist visit during the baseline period (RR (95% CI) 0.77 (0.72, 0.82). These results remained unchanged even after adjusting for demographic, clinical, and other factors (adjusted RR (95% CI) 0.78 (0.74, 0.85)). After 20 months, only 50% of patients continued to receive folic acid.
  
  
  CONCLUSIONS
  In a nationwide VHA cohort of new users of oral MTX, many patients did not receive folic acid or discontinued it over time. Rheumatologists were more likely to prescribe folic acid than other providers. These data highlight the need to improve patient safety for users of methotrexate by standardizing workflows for folic acid supplementation.
authors.affiliation: Department of Medicine, University of California San Francisco, San Francisco, CA, United States of America.|Department of Medicine, Veterans Affairs Medical Center-San Francisco, San Francisco, CA, United States of America.
authors.forename: Gabriela
authors.identifier: http://orcid.org/0000-0003-2687-5043
authors.initials: G
authors.lastname: Schmajuk
authors.affiliation: Department of Medicine, University of California San Francisco, San Francisco, CA, United States of America.
authors.forename: Chris
authors.initials: C
authors.lastname: Tonner
authors.affiliation: Department of Medicine, Veterans Affairs Medical Center-San Francisco, San Francisco, CA, United States of America.
authors.forename: Yinghui
authors.initials: Y
authors.lastname: Miao
authors.affiliation: Department of Medicine, University of California San Francisco, San Francisco, CA, United States of America.
authors.forename: Jinoos
authors.initials: J
authors.lastname: Yazdany
authors.affiliation: School of Public Health, Yale University, New Haven, CT, United States of America.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Gannon
authors.affiliation: Department of Medicine, University of California San Francisco, San Francisco, CA, United States of America.
authors.forename: W John
authors.initials: WJ
authors.lastname: Boscardin
authors.affiliation: Department of Medicine, University of California San Francisco, San Francisco, CA, United States of America.|Department of Medicine, Veterans Affairs Medical Center-San Francisco, San Francisco, CA, United States of America.
authors.forename: David I
authors.initials: DI
authors.lastname: Daikh
authors.affiliation: Department of Medicine, University of California San Francisco, San Francisco, CA, United States of America.|Department of Medicine, Veterans Affairs Medical Center-San Francisco, San Francisco, CA, United States of America.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Steinman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy; D015331:Cohort Studies; D004334:Drug Administration Schedule; D005260:Female; D005492:Folic Acid / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use*; D012189:Retrospective Studies; D014728:Veterans / Q000706:statistics & numerical data
chemical_list: D018501:Antirheumatic Agents; D005492:Folic Acid; D008727:Methotrexate