BATON ROUGE - Companies that make prescription painkillers and their allies have contributed more than $1 million to Louisiana candidates and hired an average of 40 lobbyists yearly in the state since 2006 to push their policies.

The findings are part of a joint investigation by The Associated Press and the Center for Public Integrity. The investigation determined the organizations spent $880 million and hired an annual average of 1,350 lobbyists in state capitals around the country from 2006 through 2015.

Lobbying by the organizations in Louisiana ranked fourth, when the lobbyist hires were considered against all lobbying registrations across states.

The spending comes as Louisiana's use of opioids reached the sixth-highest in the country last year, with more than 4.8 million prescriptions issued, more than 1 prescription per capita.