A new analysis by the National Institutes of Health (NIH) in Bethesda, Maryland, reinforces previous studies showing that productivity may lag as labs get bigger. The results suggest that NIH could fund thousands more researchers without any drop-off in scientific output if it capped the total number of grants an investigator could receive, an NIH official says.

“We could potentially fund more investigators, particularly new and midcareer investigators, than we are currently funding and, if anything, increase the overall scientific output of the enterprise,” said Michael Lauer, chief of NIH’s Office of Extramural Research (OER), during a presentation last week to the NIH Advisory Committee to the Director (ACD). After the meeting, Lauer told Science Insider that he wanted to “get this conversation going” but that NIH hasn’t decided whether to change existing policies on the maximum level of NIH support.

Despite more applications, the annual number of principal investigators that NIH funds hasn’t risen much since 2003, when the agency’s budget flattened, and now stands at about 26,000. That phenomenon has led to record-low success rates—fewer than one in five proposals is now funded—and what some observers call “hypercompetition.”

To address its concern for young scientists, in 2008 NIH began to essentially give extra points to proposals from young investigators. That policy has halted a slide in the portion of NIH grantees under 45 (the dark red line in the graph below). However, investigators between the ages of 45 and 60 are now in decline, whereas the percentage above 60 is expanding, Lauer noted. “Arguably, midcareer investigators are being crowded out of the system,” he said.

At the same time, several studies have found that productivity suffers as labs get bigger. OER analysts assigned points to grants by type and size to get what NIH calls a Research Commitment Index, or RCI. Tallying those numbers instead of grant dollars, says Lauer, doesn’t penalize investigators doing clinical trials and studies with large animals that are more expensive to carry out than other projects funded with the same type of grant.

One eye-opening result is that older investigators now tend to score highest, with those in their mid-60s reaching a peak RCI of 12.5 (the blue line in the graph below). That’s a change from 1990, when investigators ages 45 to 65 all had roughly the same RCI score of about nine (red line).

Lauer’s team then plotted nearly 2 decades’ worth of investigators’ yearly RCI scores against a new NIH measure of the scientist’s influence that normalizes citations by field, called a Relative Citation Ratio (see p. 13 here). They found that productivity rises more slowly once an investigator has an RCI above seven, equivalent to one bread-and-butter R01 grant. This suggests “a kind of inefficiency,” Lauer says. Putting a limit on an investigator’s RCI or grant score, Lauer told the ACD, could potentially allow NIH to fund 10% to 15% more investigators, or between 2600 and 3900 more researchers, without lowering overall productivity.

A well-funded lab would not be cut, Lauer said. But investigators who submitted a new request might be told that they had reached the NIH ceiling. NIH’s National Institute of General Medical Sciences (NIGMS) already has policies like this, and an internal NIH working group led by Lauer and NIGMS Director Jon Lorsch is looking at whether they should be expanded. There is an NIH-wide policy requiring extra scrutiny of proposals from investigators who already have $1 million in direct support, but NIH admits that it’s not clear how much impact it has had.

Some ACD members noted that Lauer’s approach would cap funding for their own labs. Russ Altman of Stanford University in Palo Alto, California, worried that “a potential cesspool of confounders” might skew NIH’s analysis. The above-60, well-funded scientists might be those who made it through a culling that leaves the best scientists standing, he said. And Linda Griffith of the Massachusetts Institute of Technology in Cambridge pointed out that senior scientists often head big, infrastructure-heavy projects that support many junior investigators.

In response, NIH Director Francis Collins said that although such team efforts are needed, he worries that the current system may delay the desired progression of early-career scientists. “If the model is that the senior investigator continues to be the principal investigator, and the junior scientist is not quite independent, then what are we propagating?” he asked.