Strengths and Limitations
The study’s strengths include the strong theory base of the intervention
informed by an initial pilot study (see Blinded for review) and the
mapping of these identified constructs on the intervention content.
Further, this study provided one of the first theory-based interventions
tackling the fundamental diabetes management behaviour of carbohydrate
counting. It offered a test of the utility of the integrated theoretical
model in informing health behaviour change in a cultural context where
there is a dearth of theory-based health behaviour change interventions
for T2D adults. Additional strengths were RCT design and the use of
face-to-face interviews by trained health care providers allowing
participants to check their understanding of the questions posed, likely
improving the reliability of responses.
The relatively small sample size and lack of objective measurements of
HbA1c and fasting blood sugar (FBS) is a limitation of the current
study. FBS and HbA1c are common outcome measures in diabetes. FBS
fluctuates in a short period, and regular test are required for judgment
purposes. With respect to limited resources and participants’
possibility of nonattendance for regular visits, we did not measure
blood sugar. However, HbA1c changes are measurable after three months.
Our post-intervention measurements were performed two months following
the latest intervention session, due to time restrictions. Thus, we
thought that two months might not accurately demonstrate the effects of
TPB intervention on HbA1c.
Our post-intervention measurements were scheduled to be only performed
on one occasion, two months post-intervention. Besides, study
participants were all IDS members. These individuals are usually highly
motivated about their diabetes management, bringing into question the
generalizability of the findings to other adults diagnosed with T2D not
aligned with a national diabetes organization.