Nielsen New 375

Nielsen is taking the unprecedented action of reissuing seven months of Los Angeles radio ratings. The expansive ratings redo comes after Nielsen removed four homes from its L.A. PPM panel, effective with the April survey data released Monday.

Nielsen says it completed an impact analysis of back data and the homes didn’t meet its standards. As a result Nielsen says it will reissue seven monthly survey periods of L.A. ratings, covering the period from October 2017-March 2018.

“An internal review determined that these homes did not meet our compliance and data integrity standards,” the company told clients in a product notification. Nielsen says it is conducting a review of the homes and because the review is ongoing, it can’t share more details at this time.

While the company caught the suspect households and removed them before Monday’s release of the April ratings, an impact analysis of back data determined seven survey months of ratings included the tainted households, spanning October 2017-March 2018. The company will begin reissuing ratings from those months starting with the March 2018 survey on May 22.

While the company has reissued ratings in the past, reconfiguring seven months of numbers is unprecedented. “The integrity of our data is a top priority,” a Nielsen spokesperson said in a statement emailed to Inside Radio.

The company issued the following schedule of dates for the reissued ratings: March 2018 Monthly Data are expected to release Tuesday May 22; February 2018 Monthly Data in the week of May 28; January 2018 Monthly Data in the week of June 4; Holiday 2017 Monthly Data in the week of June 11; December 2017 Monthly Data in the week of June 18; and November 2017 and October 2017 Monthly Data in the week of June 25.

This isn’t the first time Nielsen has removed households from the L.A. sample. In Aug. 2016, the measurement giant removed nearly three-dozen PPM households from the L.A. panel during the August survey after finding “irregular compliance patterns” among 35 L.A. panelists, which it attributed to an “isolated personnel issue” within its own ranks.