According to the article, litigation increased in the 1990's. That happened to coincide with the greater funding of nursing care. The best correlate of litigation is assets not quality. The tort system is a really a system of lawyer plunder.
"High-quality nursing homes get sued almost as often as low-quality nursing homes, a new study shows. Researchers say the finding illustrates that litigation, or the threat of litigation, doesn't lead to improvements in patient care. Nor does it appear that better nursing homes are rewarded for superior care in terms of fewer lawsuits."