My thoughts on the most likely reasons why these trends are observed.
- There was a 'play out' in innovation related to either anesthesia care or post-op care that meant that the trend toward outpatient surgeries 'stalled out.'
- There was a shift in the relative power in the health care marketplace. In 1990, the health insurers held relatively more power, whereas by 2000 the power had shifted to providers (defined as hospital and most notably health systems.). This is similar to Austin's 'demise of managed care' explanation.