HbA_1c Change in Patients With and Without Gaps in Pharmacist Visits at a Safety-Net Resident Physician Primary Care Clinic

HbA_1c

The mean change in HbA_1c between the 2 groups was not statistically significant (-1.5% ± 2.0% in the CCC vs -1.0% ± 2.1% in the GCC, P = .36) (Table 3). However, an absolute mean HbA_1c reduction of 1.3% was observed in both groups combined at the end of the study. Figure 1 shows a D-I-D model of the 2 groups. Based on the output, the P value of .11 on the interaction term (time*group) indicates that the D-I-D in HbA_1c change from baseline to final between the CCC and GCC is not statistically different. However, the magnitude of the difference calculated from the LSMEANS results showed a trend. The HbA_1c from baseline to final measurement of patients in the GCC declined by 0.97 percentage points (from 9.94% to 8.97%), while those in the CCC saw their HbA_1c decline by 1.48 percentage points (from 9.96% to 8.48%), for a D-I-D of 0.51. In other words, those in the GCC had an HbA_1c that decreased by 0.51% less than that of patients in the CCC, suggesting that the CCC shows a steeper line declining from baseline to final HbA_1c compared to the GCC, whose line declines less sharply.

In the subgroup analysis of patients whose baseline HbA_1c was ≥ 8%, about 42% in the CCC and 37% in the GCC achieved an HbA_1c < 8% (P = .56) (Table 4). Approximately 83% of patients in the CCC had some degree of HbA_1c improvement—the final HbA_1c was lower than their baseline HbA_1c—whereas this was observed in about 75% of patients in the GCC (P = .19). Of patients whose baseline HbA_1c was < 8%, there was no significant difference in proportion of patients maintaining an HbA_1c < 8% between the groups (P = .57), although some increases in HbA_1c and HbA_1c changes were observed in the GCC (Table 5).

Health care utilization

Patients in the CCC visited pharmacists 5 times on average over 12 months, whereas patients in the GCC had an average of 6 visits (5 ± 2.6 in the CCC vs 6 ± 2.6 in the GCC, P = .01) (Table 6). The mean length between any 2 adjacent visits was significantly different, averaging about 33 days in the CCC compared to 64 days in the GCC (33.2 ± 10 in the CCC vs 63.7 ± 39.4 in the GCC, P < .001). As shown in Figure 2, the GCC shows wider ranges between any adjacent pharmacy visits throughout until the 10th visit. Both groups had a similar number of visits with primary care physicians during the same time period (4.6 ± 1.86 in the CCC vs 4.3 ± 2.51 in the GCC, P = .44). About 30% of patients in the CCC and 47% in the GCC had at least 1 visit to the emergency room or urgent care or had at least 1 hospital admission, for a total of 124 acute care utilizations between the 2 groups combined. Only a small fraction of acute care visits with or without hospitalizations were related to diabetes and its complications (23.1% in the CCC vs 22.0% in the GCC).

Discussion

This is a real-world study that describes HbA_1c changes in patients who maintained pharmacy visits regularly and in those who had a history of a 3-month or longer gap in pharmacy visits. Although the study did not show statistically significant differences in HbA_1c reduction between the 2 groups, pharmacists’ care, overall, provided mean HbA_1c reductions of 1.3%. This result is consistent with those from multiple previous studies.^10-13 It is worth noting that the final HbA_1c was numerically lower in patients who followed up with pharmacists regularly than in patients with gaps in visits, with a difference of about 0.5 percentage points. This difference is considered clinically significant,¹⁷ and potentially could be even greater if the study duration was longer, as depicted by the slope of HbA_1c reductions in the D-I-D model (Figure 1).

Previous studies have shown that pharmacist visits are conducted in shorter intervals than primary care physician visits to provide closer follow-up and to resolve any medication-related problems that may hinder therapeutic outcome improvements.^3-4,7-9 Increasing access via pharmacists is particularly important in this clinic, where resident physician continuity and access is challenging. The pharmacist-driven program described in this study does not deviate from the norm, and this study confirms that pharmacist care, regardless of gaps in pharmacist visits, may still be beneficial.