Disclosed herein are optical interference multilayer coatings employing a high refractive index material comprising a NbTaZr oxide. Such coatings provide enhanced retention of favorable optical and physical properties at high temperatures. Also disclosed herein are lamps comprising a light-transmissive envelope, at least a portion of the surface of the light-transmissive envelope being provided with the optical interference multilayer coating noted above. Such coatings, when used on lamps, may advantageously offer improved energy efficiencies for such lamps.