Tom Paris' line "I'm a pilot, not a doctor!" at the 26 minute mark is a parody of the running gag which all doctors in the various Star Trek series have said. It originated with Leonard McCoy on the original Star Trek (1966), and has moved on through every series since.
At various points the main musical theme featured in Star Trek: Deep Space Nine (1993) mixes in with Voyager themes, helping to tie both series together for the first time.
The Doctor asks the EMH Mark-2 if the Federation is at war with the Romulans, and the EMH-2 replies, "No, the Romulans haven't gotten involved in our fight with the Dominion." This would soon change, when Captain Sisko draws the Romulans into the war in In the Pale Moonlight (1998), which aired four months after this Voyager episode.
EMH Mark-2 was apparently designed with the ability to deactivate himself; Voyager's EMH had to be upgraded with this ability after the series' start.
This episode introduces the Hirogen, a formidable adversary for the Voyager crew.