Injectable medication for the treatment of multiple sclerosis: the influence of self-efficacy expectations and injection anxiety on adherence and ability to self-inject

Ann Behav Med. 2001 Spring;23(2):125-32. doi: 10.1207/S15324796ABM2302_7.


The management of many chronic illnesses involves medications that must be injected on a frequent basis. With fewer support resources available, patients are increasingly being obliged to manage injectable medications themselves. Interferon beta-1a (IFNbeta-1a), recommended for the treatment of multiple sclerosis (MS), must be injected intramuscularly on a weekly basis. Patients are generally advised and taught to self-inject, if possible. This longitudinal study examined cognitive and affective contributions to the ability to self-inject and adherence to IFNbeta-1a over 6 months following initiation of medication. Participants were 101 patients with a relapsing form of MS. Injection self-efficacy expectations, injection anxiety, adherence expectations, method of injection administration, and 6-month adherence to IFNbeta-1a were fitted to a path analytic model. Pretreatment injection self-efficacy expectations were significantly related to 6-month adherence. This relation was mediated by the patient's ability to self-inject. Patients 'experienced level of injection anxiety was related to adherence but not to method of injection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic / therapeutic use
  • Adult
  • Anxiety / etiology
  • Anxiety / psychology*
  • California
  • Chi-Square Distribution
  • Factor Analysis, Statistical
  • Female
  • Humans
  • Injections, Intramuscular / psychology*
  • Interferon beta-1a
  • Interferon-beta / therapeutic use
  • Male
  • Models, Psychological
  • Multiple Sclerosis / drug therapy*
  • Patient Compliance*
  • Self Efficacy*


  • Adjuvants, Immunologic
  • Interferon-beta
  • Interferon beta-1a