A quality improvement and cost-cutting initiative that has grown to include more than 333 hospitals has saved more than $9 billion and has reduced rates of central line-associated bloodstream infections, pressure ulcers and other types of patient harm.

That's according to newly released data from the QUEST collaborative (PDF), a project of the Charlotte, N.C.-based Premier healthcare alliance. Launched in 2007 with an initial group of 157 hospitals, QUEST tracks participants across a range of measures, looking at progress in harm, mortality, readmissions, patient experience, cost of care and adherence to evidence-based practices. (QUEST stands for quality, efficiency, safety and transparency.)

Sepsis rates have fallen 23% from the baseline among participating hospitals, while central line-associated bloodstream infection rates have dropped nearly 60%, says the latest data, released 4½ years into the program.

In other areas, such as patient experience, progress has proved to be more challenging, said Susan DeVore, Premier's president and CEO. “We did see some improvement, though,” she said, pointing to a 3% overall jump in a composite measure of patient experience among participating facilities.

Mean costs per discharge were more than $1,110 less, on average, among participants, when compared with national trends, Premier said.

Premier also touted QUEST hospitals' gains in mortality. Risk-adjusted mortality rates were 10% lower among participants than among a group of similar nonparticipating hospitals, Premier said, basing its calculations on publicly available Medicare data. Premier said the program has saved 92,000 lives since its inception, up from an estimated 24,820 lives saved in January 2012, when Premier released data from the first three years of QUEST.

The program's ability to move the needle on mortality was disputed in March of last year, when researchers from the Harvard School of Public Health, Boston, released a study concluding that the CMS/Premier hospital quality incentive demonstration project, or HQID,—upon which QUEST is based—led to no long-term reductions in 30-day mortality rates when compared with hospitals that were paid under the traditional fee-for-service model.

Premier sharply disagreed with the study's claims, arguing that HQID-participating hospitals had reached mortality targets sooner than other facilities, even if most hospitals eventually reached the same endpoint.

In addition, Premier said QUEST has built significantly on the process-measure framework of HQID, refining its measurement of mortality by looking at drivers such as sepsis and respiratory conditions.