The relationship between health care spending and quality of care is "totally unclear," say researchers in a Reuters Health  article about their meta-analysis of 61 studies that compared health care spending with outcomes on both small hospital-wide scales and broader state-wide levels.

Some of the studies looked at whether hospitals that spent more money per patient had fewer in-hospital deaths, or if their physicians and nurses better followed guidelines. Others compared states' Medicare spending with how well their older residents were treated for a range of conditions.

"The bottom line was that no matter how you drill down into the results, at every level the results are just all over the map," Peter S. Hussey, PhD, the study's lead investigator, told Reuters Health.

Twenty-one of the 61 studies showed higher spending was tied to better outcomes for patients, such as fewer deaths. However, 18 studies found a link between more spending and worse outcomes, and 22 showed no difference or an unclear association based on spending.

Many of the studies compared certain types of spending with potentially unrelated outcomes. Others didn't take into account how sick patients were initially when looking at how they fared in different situations, the article says.

Hussey and colleagues conclude that future studies should focus on what types of spending are most effective in improving quality and what types of spending represent waste.

The findings are published in the January 1 issue of Annals of Internal Medicine.