Overall earnings looked just a little weaker at the biggest U.S. health insurers in the first quarter than they did in the first quarter of 2014, according to analysts at Mark Farrah Associates.

The analysts compared first-quarter results for Aetna Inc. (NYSE:AET), Anthem Inc. (NYSE:ANTM), Cigna Corp. (NYSE:CI), Health Care Service Corp., Humana Inc. (NYSE:HUM), Kaiser Permanente and UnitedHealth Group Inc. (NYSE:UNH).

See also: Big health insurers look OK 

Profit margins shrank at a majority of the plans, the analysts say in their latest market review. The first quarter profit margin fell to 5.3 percent, from 5.4 percent, at Aetna, for example, and to 6.5 percent, from 8 percent, at Kaiser.

But the profit margin increased to 4.5 percent, from 3.9 percent, at Anthem, and to 5.8 percent, from 4.8 percent, at UnitedHealth.

The analysts were also able to get enough Patient Protection and Affordable Care Act (PPACA) exchange enrollment data to create an exchange plan enrollment table for the companies.

First-quarter exchange plan enrollment totaled 950,000 at Aetna, 944,100 at Humana and 898,000 at Anthem.

See also: 3 important health enrollment findings

Major PPACA commercial health insurance market provisions took effect in January 2014. The first quarter of 2015 produced the first batches of financial data that analysts can use to track year-over-year trends in health insurer performance under the new PPACA rules.

PPACA created three “three R’s” risk-management programs that are supposed to buffer insurers against the changes: a temporary reinsurance program; a temporary risk corridors program; and a permanent risk-adjustment program. 

The first-quarter results include the fees insurers have paid for the programs, but they don’t include the cash payments the companies hope to get from the reinsurance program, or the cash transfers the companies could get or pay into the risk corridors and risk-adjustment programs.