Eligible participants in MATCH were Mexi-
can Americans in metropolitan Chicago with
type 2 diabetes, aged 18 years or older, who
were being treated with at least 1 oral hypo-
glycemic agent. We defined ethnic identity as
having been bom in Mexico or having at least
1 parent or 2 grandparents bom in Mexico. To
ensure that lack of access to care did not pose
a barrier to diabetes self-management, we re-
quired participants to have health insurance or
to receive primary care through a free clinic or
public facility at the time of enrollment. Ex-
clusions for participation were active treatment
of schizophrenia, inability to provide informed
consent, previous major end-organ complica-
tions of diabetes such as end-stage renal disease
or stroke, or another household member al-
ready participating in MATCH. To reduce the
possibility of interruption in the intervention,
we excluded participants with plans for ex-
tended travel in the next 12 months or who
had lived in Mexico for more than 4 months in
the 2 years prior to enrollment. Recruitment
strategies for the study are described elsewhere,26
and consisted of direct mailings, outreach at
community events and churches, partnerships
with primary care clinics, and direct outreach
by the CHWs themselves, conducted between
January 2006 and September 2008. We ran-
domized 144 participants and followed them
for 2 years. The study was powered at 80%
to detect a difference of 1% in HbAlc level
between the intervention and placebo group,
allowing for a 20% dropout rate in each arm
at a = 0.025 to adjust for 2 primary outcomes.
Participants were told that the study was
comparing 2 forms of diabetes education and
were blinded to the study hypothesis.
After obtaining informed consent, bilingual
research assistants collected baseline evalua-
tions in 2 separate encounters, approximately
30 days apart. At the second visit, research staff
collected electronic pill caps and audited glu-
cose monitors for adherence. We conducted
most evaluations in participants’ homes; 12
participants completed examinations in an
alternative community setting or at Rush
University Medical Center. After the full initial
evaluation was completed, we randomized
participants 1 to 1 to receive either the CHW
visits (intervention arm) or the newsletter
(control arm). Randomization used a permuted
block design with block sizes of 4 and 6 in
a single randomization scheme. The Rush Pre-
ventive Medicine Data Management Center
generated randomization lists. Research assis-
tants blinded to participants’ group assignments
collected outcome data at 12 and 24 months
after randomization.
To enhance retention in this vulnerable
population, we obtained multiple contacts for
each participant, and research assistants
called every 3 months to update this informa-
tion. If a participant could not be reached, we
implemented an aggressive lost-to-follow-up
procedure. When participants relocated, we
obtained outcome interviews by telephone,
physical measures from physicians in then-
new community, and HbAlc results through
a national reference laboratory. As a result of
these methods, 121 participants (84%) com-
pleted at least 1 follow-up examination within
2 years. We obtained follow-up HbAlc mea-
surements for 79.5% of participants in the
intervention arm and 85.9% in the control arm
(P= .306). Figure A (available as a supplement
to the online version of this article at http://
www.ajph.org) shows the CONSORT diagram,
documenting flow of participants from
recruitment through final data collection.