Injectable medication for the treatment of multiple sclerosis: the influence of self-efficacy expectations and injection anxiety on adherence and ability to self-inject.
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.
Mohr
D C
DC
University of California, San Francisco, USA. dmohr@itsa.ucsf.edu
Boudewyn
A C
AC
Likosky
W
W
Levine
E
E
Goodkin
D E
DE
D000276:Adjuvants, Immunologic / Q000627:therapeutic use; D000328:Adult; D001007:Anxiety / Q000209:etiology / Q000523:psychology*; D002140:California; D016009:Chi-Square Distribution; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular / Q000523:psychology*; D000068556:Interferon beta-1a; D016899:Interferon-beta / Q000627:therapeutic use; D008297:Male; D008960:Models, Psychological; D009103:Multiple Sclerosis / Q000188:drug therapy*; D010349:Patient Compliance; D020377:Self Efficacy
D000276:Adjuvants, Immunologic; D016899:Interferon-beta; D000068556:Interferon beta-1a