Delays in protease inhibitor use in clinical practice

OBJECTIVE: To determine the clinical factors associated with delayed protea se inhibitor initiation. DESIGN: Chart review and telephone survey. SETTING: General medicine practice at an academic medical center in Boston, Mass. PATIENTS: One hundred ninety patients living with HIV and a viral load of m ore than 10,000 copies/ml. MEASUREMENTS AND MAIN RESULTS: The main outcome measurement was time to fir st protease inhibitor prescription after first elevated HIV viral load (>10 ,000 copies/ml). In this cohort, 190 patients had an elevated viral load (m edian age 39; 87% male: 12% history of injection drug use; 63% AIDS; 53% wi th depression: 17% history of pneumocystis pneumonia; 54% CD4 <200). In Cox proportional hazards modeling, significant univariate correlates for delay ed protease inhibitor initiation were higher CD4 cell count (hazard ratio [ HR] 2.38 for CD4 200-500 compared with <200, 95% confidence interval [CI] 1 .59, 3.57: and HR 8.33 for CD4 >500; 95% CI 2.63, 25.0), higher viral load (HR 0.43 for each 10-fold increase: 95% CI 0.31, 0.59), injection drug use (HR 2.08; 95% CI 1.05, 4.17), AIDS (RR 0.24: 95% CI 0.15, 0.36), and histor y of pneumocystis pneumonia (HR 0.32: 95% CI 0.21, 0.49). In multivariate m odels adjusted for secular trends in protease inhibitor use, factors signif icantly associated with delay of protease inhibitor initiation (p < .05) we re higher CD4 cell count (Tor CD4 200-500, HR 2.63; 95% CI 1.61, 4.17: for CD4 >500, HR 11.11: 95% CI 3.57, 33.33), higher viral load (HR 0.66 for eac h 10-fold increase: 95% CI 0.45, 0.98), history of pneumocystis pneumonia ( HR 0.57: 95% CI 0.37, 0.90), history of depression (HR 1.49; 95% CI 1.03, 2 .13), and history of injection drug use (HR 2.70; 95% CI 1.35, 5.56). CONCLUSIONS: HIV-infected patients with higher CD4 cell counts or a history of depression or history of injection drug use have significant and length y delays of protease inhibitor therapy. Although some delays may be clinica lly appropriate, enhancement of provider and patient education might prove beneficial. Further research should examine reasons for delays in protease inhibitor initiation and their appropriateness.