Regional changes over time in initial virologic response rates to combination antiretroviral therapy across Europe.
BACKGROUND
Changes in virologic response to initial combination antiretroviral therapy (cART) over calendar time may indicate improvements in cART or emergence of primary resistance. Regional variations may identify differences in available antiretroviral drugs or patient management.


METHODS
Virologic response (viral load < 500 copies/mL) 6 to 12 months after starting cART was analyzed in antiretroviral-naive EuroSIDA patients. Analyses were stratified by region (south, central west, north, east) or time started cART (early, 1996-1997; mid, 1998-1999; late, 2000-1904).


RESULTS
Virologic suppression was achieved by 60% of 2102 patients: 57% south (n = 560), 61% central west (n = 466), 63% north (n = 606), 58% east (n = 470) (P = 0.091). An increase was observed over time: 52% early cART, 56% mid cART, 69% late cART (P < 0.001). Overall, there were significant effects of region (P = 0.026) and time (P < 0.001) on virologic response after adjustment for confounders. Stratified by period, regional differences were less evident (early cART, P = 0.967; mid cART, P = 0.291; late cART, P = 0.163). Stratified by region, temporal changes were observed (south, P = 0.061; central west, P < 0.001; north: P = 0.070; east, P = 0.001).


CONCLUSIONS
There was some evidence of regional differences in initial virologic response to cART. Improvements over time were observed, suggesting that so far, the effect of primary resistance has not been of sufficient magnitude to prevent increasing suppression rates.
Bannister
Wendy P
WP
Department of Primary Care and Population Sciences, Royal Free and University College Medical School, London, UK. w.bannister@pcps.ucl.ac.uk
Kirk
Ole
O
Gatell
Jose M
JM
Knysz
Brygida
B
Viard
Jean-Paul
JP
Mens
Helene
H
Monforte
Antonella D'Arminio
AD
Phillips
Andrew N
AN
Mocroft
Amanda
A
Lundgren
Jens D
JD
D019380:Anti-HIV Agents / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D024882:Drug Resistance, Viral; D005060:Europe / Q000453:epidemiology; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000453:epidemiology* / Q000821:virology; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D008297:Male; D013997:Time Factors; D019562:Viral Load
D019380:Anti-HIV Agents