A population-based cervical cancer screening program in a district hospital in Tamil Nadu is being evaluated. The program uses Pap smear as the primary screening test. Among 5,000 women screened, 450 had abnormal results. Of these 450, 90 were confirmed to have cervical intraepithelial neoplasia (CIN) grade 2 or higher on colposcopy-guided biopsy. The remaining 360 had benign findings. What is the most appropriate next step to improve the efficiency of this screening program?