The independent report from the Commission recognises that accidental fire deaths are at their lowest level since the late 1950s.
Mr Khan said: "It is good to see that most Fire and Rescue Services are improving. I would like to congratulate everyone involved in helping us get this improvement.
"The Commission rightly recognises the achievements of the Service in helping to drive down fire incidents and fire deaths, while making improvements in efficiency.
"We share the Audit Commission's continuing view that a more representative workforce makes it easier for the service to connect with the different communities most at risk from fire.
"It is clear from the report that while many Fire and Rescue Services are improving their performance on community engagement and are working hard to make connections with the most vulnerable sections of our society much still needs to be achieved to create a more representative workforce."
The Audit Commission has published the results of three assessment processes they have undertaken for Fire and rescue Authorities in the form of a scorecard for each authority.
The score cards show:
32 services (71%) assessed as improving well;
16 services (44 assessed) achieved the highest marking for service assessment;
Greater Manchester, Kent & Medway and Merseyside have achieved the highest Use of Resources scores for the last three consecutive years.