Data-driven service redesign and pharmacist workforce expansion in independent community pharmacies: evidence from a Pareto-guided intervention in Thailand

Background Independent community pharmacies are essential to Thailand’s primary healthcare network but face sustainability challenges due to intense price competition, limited economies of scale, and workforce shortages. This study evaluated whether a Pareto-guided, data-driven service design, combined with increased pharmacist staffing, could improve the financial stability and service performance of independent pharmacies. Methods A quasi-experimental, pre–post design with an Interrupted Time Series (ITS) framework was applied using 24 months of transactional data (September 2023–August 2025) from Thai Rungrueang Pharmacy Company Limited . The intervention, initiated on 1 September 2024, involved increasing the number of pharmacists per day from one to two in the two highest-revenue branches, focusing on high-margin stock-keeping units (SKUs) identified via Pareto analysis. Key indicators included monthly revenue, profit, gross margin (%), and repeat-purchase ratio (%). ITS regression models assessed changes in level and slope post-intervention, controlling for autocorrelation and seasonal effects. Results Across the observation period, total revenue was THB 65,936,881.51, and gross profit was THB 32,416,954.25. The overall mean gross margin was 49.40% (median 49.71%). The top 5.00% of SKUs (≈134 items) accounted for 60.13% of gross profit, confirming a strong Pareto effect. Following the pharmacist expansion, the mean monthly profit increased from THB 2,587,200.45 (pre-intervention) to THB 2,707,540.91 (post-intervention), a 4.65% increase. The mean monthly gross margin improved from 48.72% to 49.83% (+1.11 percentage points). The ITS model detected a statistically significant level increase in gross margin of +0.98 percentage points (p = 0.042), while the slope remained positive but non-significant (β = +0.03, p = 0.080). The repeat-purchase ratio for high-margin SKUs increased from 26.40 % to 33.90 % (+7.50 percentage points, +28.40 % relative gain), and monthly profit variance declined by 21.00 %, indicating greater financial stability. Conclusions Targeting pharmacist-led services toward Pareto-dominant, high-margin products—combined with strategic workforce expansion—improved profitability, gross-margin stability, and repeat purchasing. These findings suggest that aligning service design with data-driven profitability analytics may strengthen the resilience and sustainability of community pharmacy services within Thailand’s evolving primary healthcare system and other emerging-market contexts.