To the Editors:
We read the correspondence from Sayana et al1 with interest. Similar to their study, our program evaluated the possibility of increasing the duration between monitoring visits in our clinic population from 3 to 4 months to every 6 months. As antiretroviral therapies (ARVs) have improved, patients have achieved a better health status for prolonged periods. The Department of Health and Human Services Guidelines currently recommend that monitoring blood work be performed every 3–6 months in patients on ARVs. In clinically stable patients with suppressed HIV RNA levels, the guidelines suggest CD4 cell counts can be monitored every 6–12 months. For adherent patients with suppressed HIV RNA levels and stable clinical and immunologic status for more than 2–3 years, the interval for HIV RNA monitoring may be as infrequent as every 6 months.2
To assess the feasibility and safety of prolonging the interval between both laboratory monitoring and clinic visits for stable patients in our program, we conducted a retrospective chart review on patients meeting specified criteria. Given the increased risk for age-related concurrent conditions, the study population was confined to patients on ARVs between those aged 25 and 50 years. Of the 1441 patients meeting the age criteria in 2010, 1052 (73%) were on ARVs. Only 174 (17%) of patients on ARVs had an RNA level <400 copies per milliliter and CD4 cell count >350 cells per cubic millimeter on their last laboratory monitoring check.
Charts were reviewed to determine if the 174 patients met additional parameters for stability. Screening criteria included an HIV RNA level <400 copies per milliliter on 2 occasions, no HIV RNA level >400 copies per milliliter, a CD4 cell count >350 cells per cubic millimeter on one occasion, no CD4 cell count level <250 cells per cubic millimeter, and no opportunistic infections for the preceding 8 months. Within the preceding 4 months, patients had to have a creatinine and aspartate transaminase within normal limits. In addition, they were also required to have hemoglobin ≥11 mg/dL, glucose ≤120 mg/dL, controlled blood pressure (systolic pressure ≤ 140 mm Hg and diastolic pressure ≤ 90 mm Hg), no evidence of substance use, and not be on any long-acting opiates.
One hundred (57.5%) of the 174 patients were ineligible because of not meeting additional screening criterion. The most frequent reasons for ineligibility were having at least one HIV RNA level >400 copies per milliliter (n = 39), uncontrolled blood pressure within 4 months of baseline (n = 33), and lacking a HIV RNA level of <400 copies per milliliter on at least 2 occasions within 8 months of baseline visit (n = 30).
Of the 74 patients (34 women and 40 men) remaining stable during the screening prebaseline review, 6 had no further follow-up visits and 31 had laboratory or blood pressure parameters at the baseline visit that fell out of the screening criteria ranges. Most common reasons were baseline diastolic pressure >90 mm Hg (n = 11), baseline glucose >120 mg/dL (n = 10), baseline CD4 <350 cells per cubic millimeter (n = 8), HIV RNA level >400 copies per milliliter (n = 8), or aspartate transaminase >45 (n = 8).
Of the 37 patients remaining stable at baseline, 2 patients had no further follow-up visits and 12 had laboratory (n = 7) or blood pressure parameters (n = 5) at the 3 month visit that fell out of the screening criteria ranges. Most common abnormal parameters included systolic pressure >140 mm Hg (n = 3), diastolic pressure >90 mm Hg (n = 3), hemoglobin <11 mg/dL (n = 2), HIV RNA level >400 copies per milliliter (n = 2), CD4 <350 cells per cubic millimeter (n = 2), and glucose >120 mg/dL (n = 2). Of the 27 patients who had acceptable parameters at the 3-month visit, 9 had abnormalities at 6 months, including hemoglobin <11 mg/dL (n = 5), diastolic pressure >90 mm Hg (n = 4), glucose>120 mg/dL (n = 3), HIV RNA level >400 copies per milliliter (n = 2), CD4 count <350 cells per cubic millimeter (n = 2), or systolic pressure >140 mm Hg (n = 2). Four of the 27 had only laboratory abnormalities.
In summary, of the initial 174 patients on ARVs meeting age and initial HIV RNA and CD4 cell count level criteria, only 37 (21%) remained eligible by chart review of additional parameters between the preceding 8 months and baseline. Subsequently, 12 (32.4%) of these 37 highly stable patients had asymptomatic abnormal laboratory (18.9%) or blood pressure (13.5%) results at 3 months that may have required medical attention.
Although lack of demonstration of optimal virologic suppression was the most frequent reason for elimination of patients during the 8-month lead in screening period, virologic failure was rare in patients meeting criteria to qualify for increasing the duration between visits. This observation supports the Department of Health and Human Services Guideline recommendations pertaining to selection criteria for prolonging the interval between HIV RNA monitoring. The few numbers of patients who were qualified by our initial criteria and the relatively high proportion of patients who were ineligible or became unstable by our parameters within a 6-month period were unexpected. Some clinics, particularly those with populations with more advanced HIV disease and a relatively high prevalence of concurrent medical conditions, may have limited number of patients on ARVs who will meet criteria for biannual monitoring.
1. Sayana S, Javanbakht M, Weinstein M, Khanlou H. Clinical impact and cost of laboratory monitoring need review even in resource-rich setting. J Acquir Immune Defic Syndr. 2011;56:e97–e98.