Persistence on therapy and propensity matched outcome comparison of two subcutaneous interferon beta 1a dosages for multiple sclerosis.
PLoS One
; 8(5): e63480, 2013.
Article
in En
| MEDLINE
| ID: mdl-23704913
OBJECTIVES: To compare treatment persistence between two dosages of interferon ß-1a in a large observational multiple sclerosis registry and assess disease outcomes of first line MS treatment at these dosages using propensity scoring to adjust for baseline imbalance in disease characteristics. METHODS: Treatment discontinuations were evaluated in all patients within the MSBase registry who commenced interferon ß-1a SC thrice weekly (nâ=â4678). Furthermore, we assessed 2-year clinical outcomes in 1220 patients treated with interferon ß-1a in either dosage (22 µg or 44 µg) as their first disease modifying agent, matched on propensity score calculated from pre-treatment demographic and clinical variables. A subgroup analysis was performed on 456 matched patients who also had baseline MRI variables recorded. RESULTS: Overall, 4054 treatment discontinuations were recorded in 3059 patients. The patients receiving the lower interferon dosage were more likely to discontinue treatment than those with the higher dosage (25% vs. 20% annual probability of discontinuation, respectively). This was seen in discontinuations with reasons recorded as "lack of efficacy" (3.3% vs. 1.7%), "scheduled stop" (2.2% vs. 1.3%) or without the reason recorded (16.7% vs. 13.3% annual discontinuation rate, 22 µg vs. 44 µg dosage, respectively). Propensity score was determined by treating centre and disability (score without MRI parameters) or centre, sex and number of contrast-enhancing lesions (score including MRI parameters). No differences in clinical outcomes at two years (relapse rate, time relapse-free and disability) were observed between the matched patients treated with either of the interferon dosages. CONCLUSIONS: Treatment discontinuations were more common in interferon ß-1a 22 µg SC thrice weekly. However, 2-year clinical outcomes did not differ between patients receiving the different dosages, thus replicating in a registry dataset derived from "real-world" database the results of the pivotal randomised trial. Propensity score matching effectively minimised baseline covariate imbalance between two directly compared sub-populations from a large observational registry.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Interferon-beta
/
Medication Adherence
/
Propensity Score
/
Multiple Sclerosis
Type of study:
Clinical_trials
Limits:
Adult
/
Female
/
Humans
/
Male
Language:
En
Journal:
PLoS One
Journal subject:
CIENCIA
/
MEDICINA
Year:
2013
Document type:
Article
Affiliation country:
Australia
Country of publication:
United States