Objective:

To assess the use of resources and the costs associated with following up patients infected with the human immunodeficiency virus after discontinuation of an antiretroviral treatment and initiation of a new one due to a lack of effectiveness or unacceptable toxicity, as compared to the costs involved in the routine follow-up of patients on antiretroviral treatment, from the Spanish National Health System perspective.

Method:

The use of resources (clinical tests, medical visits, and hospital pharmacy visits) associated with following three profiles of patients infected with the human immunodeficiency virus (stable ones, those discontinuing an existing antiretroviral treatment and being switched to a new one due to a lack of effectiveness, and those discontinuing an existing antiretroviral treatment and being switched to a new one due to unacceptable toxicity) was identified, based on clinical practice guidelines and the findings of a multidisciplinary expert panel (n = 5). The experts agreed on the main adverse events leading to discontinuation, classifying them into gastrointestinal, renal, osseous, musculoskeletal, dermatological, hepatic, lipid profile-related, neuropsychiatric and sexual alterations. Unit costs were identified from official healthcare costs databases. The cost (€, 2020) of following up each patient profile was estimated, excluding the cost of the antiretroviral treatment itself, with a time horizon of two years.

Results:

The per-patient cost of following up stable patients over two years was estimated at €4,148 (tests: €2,293; visits: €1,855). Patient follow-up after discontinuation of an existing antiretroviral treatment and initiation of a different one due to a lack of effectiveness was estimated at €5,434 (tests: €2,777; visits: €2,657). The cost of follow-up after discontinuation of an existing regimen and initiation of a new one due to unacceptable toxicity varied according to the adverse event prompting the switch, ranging from €4,690 for lipid profile dysregulation, to €5,304, for musculoskeletal alterations. In this patient profile, the cost of tests ranged from €2,403 to €3,017, and that of visits from €2,287 to €2,842.

Conclusions:

The cost associated with following up of patients infected with the human immunodeficiency virus after discontinuation of an existing antiretroviral regimen and initiation of a new one is higher tan that of routine follow-up, without taking the cost of drugs into account. The treatment discontinuation rate is a relevant factor when selecting the most appropriate therapy for each patient.