Hematologic, Hepatic, Renal, and Lipid Monitoring After ART
Hematologic, Hepatic, Renal, and Lipid Monitoring After ART
In this clinical HIV cohort, routine laboratory monitoring was as frequent as recommended for hematologic, hepatic, and renal tests for the majority of patients initiating cART between 2000 and 2010, but lipid monitoring was substantially less than recommended. Specific clinical characteristics predicted the relative frequency of testing. This study evaluated a national multisite population of HIV-infected patients initiating modern cART in routine clinical care, allowing our findings to be broadly generalizable in the United States.
More than 75% of patients received the minimum number of recommended tests for hematologic, hepatic, and renal abnormalities by 1 year of cART. More than 30% received more tests than recommended by 1 year. Because we only excluded patients based on prior abnormalities for each laboratory type, these extra tests were likely driven by preceding diagnoses, coadministration of other medications, symptoms, or abnormalities on other laboratory tests. In contrast, most patients did not have an annual lipid evaluation, and only 20% of performed tests occurred in the recommended fasting state. In fact, less than half of patients received a lipid test within the first year, and among patients followed for 2 years, only 51% received a lipid test. This is similar to results from a previous study within CNICS, where 59% of patients had at least 1 non-HDL measurement during a mean 1.7 years of antiretroviral therapy. As other monitoring tests were obtained more frequently, it is unlikely that poor lipid monitoring was driven by poor visit attendance. An alternative explanation is that clinicians were hesitant to perform lipid testing in patients who were not fasting. Monitoring for lipid abnormalities seemed to improve in more recent years, but it remains substandard.
We observed patterns suggesting that clinicians were selective in the abnormalities monitored among patient subgroups. Specifically, hematologic, hepatic, and renal tests were obtained more frequently in those with older age, more advanced HIV disease, comorbidities, or boosted-PI use. As these tests are often obtained together, it is unsurprising that a predictor for receiving 1 type of test may lead to more frequent testing for all the 3 laboratory categories. Although these predictive characteristics may represent patients with better clinic attendance, these observations likely reflect increased clinician vigilance in subgroups perceived to have higher susceptibility to toxicities. Consistent with this, lipids were monitored more frequently in patients with hypertension and hyperglycemia. Similarly, the association of abacavir use with lipid and renal monitoring may reflect both the tendency to channel patients with possible renal risk to abacavir, and concerns that abacavir increases cardiovascular risk, though this is controversial.
Study limitations include the assessment of monitoring rates only among patients on their first cART without prior abnormal laboratory values; therefore, findings are not generalizable to patients on subsequent cART regimens or patients with documented laboratory abnormalities. This approach also resulted in a high rate of censoring, reflective of regimen changes and laboratory abnormalities in routine clinical practice. Although current DHHS guidelines specifically recommend fasting lipid panel, we considered both fasting and random non-HDL measurements in our analysis. Restriction to the recommended fasting lipids would have resulted in substantially lower estimates of compliance with lipid monitoring. Although our estimates may underestimate all lipid monitoring, isolated total cholesterol values provide incomplete screening for lipid abnormalities, particularly among HIV patients who often do not exhibit classic dyslipidemic patterns. Also, patients may have obtained tests outside of the CNICS clinics, potentially leading to underestimates of monitoring rates, though this is unlikely to explain the discrepancy between monitoring of lipids and other standard laboratories.
In conclusion, most patients received frequent monitoring in accordance with current guidelines for hematologic, hepatic, and renal abnormalities but not lipid abnormalities. Clinicians may be tailoring laboratory monitoring based on perceived risks; and therefore, further assessments of adverse events among patients initiating cART in routine clinical care are needed. Future research should also focus on optimizing laboratory-monitoring strategies in resource-rich settings, recognizing that research in resource-poor settings has challenged the benefit and cost-effectiveness of asymptomatic laboratory screening in all patient populations.
Discussion
In this clinical HIV cohort, routine laboratory monitoring was as frequent as recommended for hematologic, hepatic, and renal tests for the majority of patients initiating cART between 2000 and 2010, but lipid monitoring was substantially less than recommended. Specific clinical characteristics predicted the relative frequency of testing. This study evaluated a national multisite population of HIV-infected patients initiating modern cART in routine clinical care, allowing our findings to be broadly generalizable in the United States.
More than 75% of patients received the minimum number of recommended tests for hematologic, hepatic, and renal abnormalities by 1 year of cART. More than 30% received more tests than recommended by 1 year. Because we only excluded patients based on prior abnormalities for each laboratory type, these extra tests were likely driven by preceding diagnoses, coadministration of other medications, symptoms, or abnormalities on other laboratory tests. In contrast, most patients did not have an annual lipid evaluation, and only 20% of performed tests occurred in the recommended fasting state. In fact, less than half of patients received a lipid test within the first year, and among patients followed for 2 years, only 51% received a lipid test. This is similar to results from a previous study within CNICS, where 59% of patients had at least 1 non-HDL measurement during a mean 1.7 years of antiretroviral therapy. As other monitoring tests were obtained more frequently, it is unlikely that poor lipid monitoring was driven by poor visit attendance. An alternative explanation is that clinicians were hesitant to perform lipid testing in patients who were not fasting. Monitoring for lipid abnormalities seemed to improve in more recent years, but it remains substandard.
We observed patterns suggesting that clinicians were selective in the abnormalities monitored among patient subgroups. Specifically, hematologic, hepatic, and renal tests were obtained more frequently in those with older age, more advanced HIV disease, comorbidities, or boosted-PI use. As these tests are often obtained together, it is unsurprising that a predictor for receiving 1 type of test may lead to more frequent testing for all the 3 laboratory categories. Although these predictive characteristics may represent patients with better clinic attendance, these observations likely reflect increased clinician vigilance in subgroups perceived to have higher susceptibility to toxicities. Consistent with this, lipids were monitored more frequently in patients with hypertension and hyperglycemia. Similarly, the association of abacavir use with lipid and renal monitoring may reflect both the tendency to channel patients with possible renal risk to abacavir, and concerns that abacavir increases cardiovascular risk, though this is controversial.
Study limitations include the assessment of monitoring rates only among patients on their first cART without prior abnormal laboratory values; therefore, findings are not generalizable to patients on subsequent cART regimens or patients with documented laboratory abnormalities. This approach also resulted in a high rate of censoring, reflective of regimen changes and laboratory abnormalities in routine clinical practice. Although current DHHS guidelines specifically recommend fasting lipid panel, we considered both fasting and random non-HDL measurements in our analysis. Restriction to the recommended fasting lipids would have resulted in substantially lower estimates of compliance with lipid monitoring. Although our estimates may underestimate all lipid monitoring, isolated total cholesterol values provide incomplete screening for lipid abnormalities, particularly among HIV patients who often do not exhibit classic dyslipidemic patterns. Also, patients may have obtained tests outside of the CNICS clinics, potentially leading to underestimates of monitoring rates, though this is unlikely to explain the discrepancy between monitoring of lipids and other standard laboratories.
In conclusion, most patients received frequent monitoring in accordance with current guidelines for hematologic, hepatic, and renal abnormalities but not lipid abnormalities. Clinicians may be tailoring laboratory monitoring based on perceived risks; and therefore, further assessments of adverse events among patients initiating cART in routine clinical care are needed. Future research should also focus on optimizing laboratory-monitoring strategies in resource-rich settings, recognizing that research in resource-poor settings has challenged the benefit and cost-effectiveness of asymptomatic laboratory screening in all patient populations.