The impact of metrifonate therapy on caregivers of patients with Alzheimer's disease: Results from the MALT clinical trial

OBJECTIVE: To assess the impact on burden reported by caregivers of patient s with mild to moderate Alzheimer's disease (AD) who were treated with metr ifonate during a randomized double blind clinical trial. DESIGN: Randomized clinical trial, with a 2-week screening period and a 26- week double blind, placebo controlled, treatment phase. Caregivers were ass essed at baseline, at 12 weeks, and at end of trial. SETTING: Caregivers were interviewed at clinics as part of the assessment o f the patients. PARTICIPANTS: Six hundred and three caregivers of AD patients who were enro lled in the MALT trial; 591 (98%) provided data suitable for analysis at ba seline, and 546 (91%) provided data allowing for inclusion in the analysis of change scores. MEASUREMENTS: The Caregiver Burden Assessment consisted of the Screen for C aregiver Burden, including both subjective (SCB-subj) and objective (SCB-ob j) scores; the cognitive subscale of Poulshock and Deimling (PD); an abridg ed version of the Relatives Stress Scale (aRSS); assessments of time spent in providing care, including the Caregiver Activity Time Scale (CATS); and demographic and background variables on both the patient and caregiver. RESULTS: Treatment of mild to moderate AD patients with metrifonate for a d uration of 26 weeks significantly reduced the psychological burden of care to the caregivers, as measured by the SCB-subj, the PD, and the aRSS. There were no statistically significant differences on the measures assessing th e time spent in caregiving, except for the caregiver's subjective impressio n of the change in time spent providing care during the trial. When compari ng individual dose groups, most of the measures of burden showed the larges t benefits in burden for the 60/80 mg group, followed by the 40/50 mg group , and then the placebo group. However, there was no statistically significa nt dose effect. CONCLUSIONS: This study provides the first evidence from a randomized clini cal trial of any acetylcholinesterase inhibitor used in the treatment of AD demonstrating a positive impact: on the patient's caregiver as well as ben efits to the patient. These results were shown consistently across several measurement scales and were observed after six months of treatment. These f indings reinforce the clinical significance of research that has shown that metrifonate has beneficial impacts on the cognitive, behavioral, and funct ional abilities of AD patients. Because caregiver burden is a leading facto r in the decision for institutional care placement, the ability to favorabl y impact that burden through pharmacological treatment of the patient is im portant.