An investigation of spectral line broadening in plasmas is carried out within a kinetic-theory approach, based on the Bogoliubov-Born-Green-Kirkwood-Yvon (BBGKY) hierarchy. The model employs a resummation procedure to account for correlated emitter-perturber collisions. Applications to hydrogen lines indicate that such collisions strongly affect the width and the shape in the core region. This argument is supported by comparisons to numerical simulations. It is also shown that the usual collision operator models, based on a binary description of emitter-perturber collisions, can be extremely inaccurate. The present model, in a better agreement with numerical simulations, is suggested as an extension suitable for the design of fast and accurate numerical routines for plasma diagnostics.