Prescription drug utilisation among older Americans has reached “a plateau,” and market growth for this population during 2011-2030 will slow to “just one-fortieth” of the previous 20 years’ rate of rise, says a new study.

And this consumption slowdown will more than offset the impact of the baby-boomer generation, warns the report, from life sciences advisory firm VOI Consulting.

After 20 years of dramatic growth in US per-capita prescription drug consumption, levels have now reached saturation point, and the US market will not, for the foreseeable future, experience the sustained wave of industry-wide growth enjoyed during 1990-2010, it says.

The impact of declining utilisation growth is already being felt, and this slowdown has generally been attributed to generic competition, cost containment or a stricter regulatory environment. However, says VOI, declining utilisation growth is in fact the most important structural challenge facing the industry.

Average US consumption of prescription drugs in the over-65s during 1990-2010 rose nearly 80% on a per-person basis, from 2.3 per month to 4.1 per month, but during 2011-2030, average monthly consumption in this population will rise less than 2% over current levels, it forecasts.

Patients will continue to switch between different therapies, but the average number of prescription drugs consumed per person has essentially stabilised. This means that changes in consumption will contribute very little to industry growth over the next two decades, the report warns.

Rising per capita utilisation led to a 39% increase in prescription drug volume in the 1990s and a further 16% during the first 10 years of the 2000s, but the “utilisation plateau” means per capita consumption will add only 3.1% to industry volume in the current decade and a meagre 1.8% during 2021-2030, it adds.

The other major contributors to prescription volume growth are a larger population and demographic changes. The most notable of these is the aging baby-boomer generation which, it is widely believed, will provide a substantial boost to pharma over the next 20 years. However, says VOI, its analysis suggests that the aging population will lead to a 7% increase in volume during the current decade and 5% thereafter - far too low to offset the utilisation growth slowdown.

In this new scenario, the most promising avenues to maintain vigorous sales growth will be aggressive pipeline management, with an emphasis on speed to market, and better adherence programmes, it advises.