Primary care continuity among pre-diabetics and the likelihood of progressing to type 2 diabetes within 3 years

Context. The transition from pre-diabetes (pre-DM) to type 2 diabetes (T2D) can be prevented or delayed through lifestyle modifications. Primary care and continuity of care may help patients maintain an HbA1c within the pre-diabetic range.

Objective. To determine whether continuity of care impedes progression to T2D. Study Design & Analysis. Multivariate logistic regression of a retrospective cohort of primary care patients.

Setting or Dataset. Data come from the Geisinger healthcare system’s EHR between 1997 and 2017.

Population Studied. Primary care patients with pre-DM were included in the analysis if they had an HbA1c between 5.7-6.4%, were 18-75 years, a BMI >27kg/m2, and at least one primary care visit in the 3 years prior to diagnosis (N=5889). Data were retrospectively collected for 3 years before and 3 years after diagnosis of pre-DM.

Intervention/Instrument. We measure relational primary care continuity as a count of the number of visits with the primary care provider (PCP) most frequently seen in the 3 years prior to diagnosis.

Outcome Measures. Our primary outcome of interest is a binary indicator for transition from pre-DM to T2D within 3 years, controlling for the total number of primary care and specialty visits over the 6-year period, sex, race, and ethnicity. We also control for baseline characteristics including age, hypertension, hyperlipidemia, HbA1c, and BMI. Finally, we control for the patient’s percent of weight lost at 1-year after baseline and a binary indicator variable for whether the patient lost ≥3% of their baseline weight and then regained ≥2% by year 3 of follow-up.

Results. The median age at baseline was 55, 56% identified as female, and the majority are non-Hispanic whites. At baseline 29% and 33% of the sample had hypertension and hyperlipidemia, respectively. The median baseline HbA1c was 5.9% and the median baseline BMI was 33.89 kg/m2. Each additional visit with the primary care provider most frequently seen in the 3 years before diagnosis of pre-DM is associated with a 6% decrease in the odds of transitioning to T2D within 3 years after their pre-DM diagnosis (OR=0.95; 95% CI=0.92; 0.97, p<0.000). Finally, the total number of PCP (OR=1.03; p<0.001) and specialty visits (OR=0.99, p<0.05) over the 6-year period were significant.

Conclusion. Establishing continuity of primary care prior to diagnosis of pre-DM may decrease the likelihood of transitioning to T2D.