The BedMed trial (led out of the University of Alberta and funded by both Alberta
Innovates Health Solutions, and the Canadian Institutes for Health Research) is a
pragmatic multi-provincial trial intended to determine whether bedtime antihypertensive
use, as compared to conventional morning use, reduces major adverse cardiovascular events
in community dwelling primary care patients.
BedMed-Frail, led by the same group of investigators, is a complementary but separate
randomized trial evaluating whether the risks and benefits of bedtime antihypertensive
use differ in a long-term care (LTC) population. To accomplish this, within participating
Alberta LTC and supportive living facilities, eligible residents with hypertension will
be randomized at the patient level to the antihypertensive medication timing intervention
(i.e. bedtime versus continued morning use). Trial outcomes and baseline characteristics
are drawn from routinely collected electronic health data - using both provincial
administrative health claims data and the Resident Assessment Instrument Minimum Data Set
(RAI-MDS), which is a standard instrument for collecting clinical information in Canadian
LTC facilities.
BedMed-Frail is event driven, receiving quarterly reporting of total events from the
Alberta Support for Patient Oriented Research (SPOR) Unit's Data Platform. Funding
permitting, the trial will continue until observation of 368 primary outcome events. Upon
observation of half that number, an independent data safety monitoring board (IDSMB)
chaired by Dr. James Wright (Cochrane Hypertension Review Group Co-ordinating Editor)
will examine all available outcomes. If p is ≤ 0.001 for benefit (the Haybittle-Peto
boundary - recommended to reduce the chance of stopping too early and magnifying
benefit), or if p is ≤ 0.05 for harm, the IDSMB will apply clinical judgement and make
recommendations to the steering committee on whether the trial should break early.
The outcomes of BedMed-Frail are primarily designed to be analogous to the cardiovascular
and safety outcomes monitored for in the community BedMed study. However BedMed-Frail is
also examining for differences in behaviour issues between groups. Both behavioural
problems, and blood pressure, have circadian rhythms. Blood pressure is normally lower
overnight and behavioural problems in long term care residents typically worsen during
the same period - a phenomenon known as "sundowning". Conceivably, there could be a
relationship between the two such that behaviour problems might improve, or worsen, with
bedtime antihypertensive use.