In 2007, for the first time in at least five years, insured US consumers on average paid less for their prescription drugs, even though drug costs for the year were higher, according to figures released by pharmacy benefit manager (PBM) Express Scripts.

The average copayment paid by insured patients dropped to $13.20 last year from $13.45 in 2006, ven though the total cost of a prescription increased to $55.93 from $55.01, says the firm’s annual Drug Trend Report, which says this positive trend for consumers is largely due to the increased use of generics.

“We process more than one million prescriptions every day and 63.7% are now for a generic drug versus 42% in 2002. When more generics are used, benefit plan sponsors can control plan costs without shifting these costs to consumers,” said Emily Cox, Express Scripts’ senior director of research.

US consumers’ share of the total cost of the average prescription (which includes ingredients such as billed ingredient cost, dispensing fee and sales tax) fell from 24.5% in 2006 to 23.6% last year, which also saw the smallest recorded year-to-year increase in the total cost, at 1.6%, compared to 2.2% in 2006, 2.8% in 2005 and 4.8% in both 2004 and 2003.

Patient copayments for generic drugs increased from $6.71 to $7.57 during 2002-7, but for preferred branded drugs they rose from $14.66 to $19.18, and for non-preferred branded medicines the increase was $11.28, from $17.16 to $28.44 to the five years, the report also finds.

“Many consumers currently paying more for a brand drug can easily switch to a less expensive generic drug with a lower copayment without negatively impacting health outcomes. The generic potential in many drug classes ranges from 70% to as high as 95% based on widely-accepted clinical guidelines,” said Ms Cox.

The study also examines copayment trends involving high-cost speciality drugs, which have become the subject of controversy this month following a report in the New York Times that more insurers are introducing “Tier 4” schemes, under which they charge patients an average of 20%-33% of expensive drugs’ costs instead of the standard copayment. Insurers claim that this procedure helps keep costs down for their other members, but critics, including Democratic Presidential hopeful Senator Barack Obama, point out that people with conditions such as cancer and rheumatoid arthritis are having to find thousands of dollars a month to pay for their share of the treatments. Frequently, no cheaper alternatives are available to them, particularly in the case of biological drugs, they add.

High-cost specialty drugs cost an average $1,550.28 per prescription in 2007, according to Express Scripts. The consumer share remained constant at 2.6% in 2006 and 2007 but, because the average cost of a specialty prescription increased 7.8% year over year