This analysis includes follow-up data to a median date of May 2009. Patients starting nevirapine, efavirenz or lopinavir together with exactly two nucleoside/nucleotide reverse transcriptase buy PD0325901 inhibitors (NRTIs) after 1 January 2000 were included in the analysis. Baseline was defined as either the date of first virological suppression (defined as a single viral load <500 HIV-1 RNA copies/mL) or 3 months after starting treatment,

whichever occurred later. Patients were excluded if they did not have a CD4 cell count or viral load measured in the 6 months prior to starting the new regimen or if they did not have any prospective follow-up. Treatment-experienced patients were included provided that they had not previously been exposed to any of the regimens of interest. Ethical approval for each participating centre is sought according to local regulations. Durability was measured as the rate of discontinuation of nevirapine, efavirenz or lopinavir, development of any serious non-AIDS-related adverse events, or worsening of other clinical or laboratory markers. The reasons for discontinuation were compared among the three regimens and the incidence of overall discontinuation

calculated. Time to discontinuation was determined using Kaplan–Meier methodology. Consistent with previous work [4,16] HM781-36B manufacturer in addition to discontinuation for any reason, analyses considered separately discontinuation because of toxicities or patient/physician choice and discontinuation because

of treatment failure. Reasons given for discontinuation were taken from patients’ notes and reported on standardized EuroSIDA follow-up forms (see forms at http://www.cphiv.dk). One reason for discontinuation per antiretroviral was collected. Discontinuation because of reported treatment failure included virological, immunological and clinical failure. Cox proportional hazards models, stratified by centre, were used to compare the risk of discontinuation among the three regimens. Patients many were followed until discontinuation of the main drug or their last recorded visit in EuroSIDA. Sensitivity analysis investigated discontinuation of any drug in the regimen and the durability of the three regimens in a subgroup of patients who were treatment naïve. The development of any serious non-AIDS clinical events or changes in clinical markers was compared among the three treatment groups using Poisson regression. Diagnosis of a non-AIDS clinical event was defined as the development of a non-AIDS-defining malignancy, pancreatitis, end-stage renal disease, grade III or IV hepatic encephalopathy, myocardial infarction, stroke or other cardiovascular disease. Changes in major clinical or laboratory markers were defined as developing or worsening anaemia, losing >10% of body weight at baseline, an increase in total cholesterol to >6.2 mmol/L or a decrease in high-density lipoprotein (HDL) cholesterol to <0.