Improvement in physician's office laboratory practices, 1989-1994

Prior to 1989, limited data existed on clinical laboratory practices in physician offices. Researchers had already identified physician's office laboratories as a growing source of clinical testing but lacked comprehensive data. This gap motivated the Centers for Disease Control and Prevention to collect new survey data. The National Ambulatory Medical Care Survey was modified to include clinical laboratory questions. No prior work had resolved how to measure quality in these settings. The Clinical Laboratory Improvement Amendments of 1988 (CLIA '88) introduced new standards, but their impact was unclear. This uncertainty drove the need for longitudinal data collection. The study aimed to track changes in laboratory practices over time.

The study aimed to assess changes in physician's office laboratory practices from 1989 to 1994. It focused on the impact of the CLIA '88 final rule implemented in 1992. Researchers sought to measure improvements in quality indicators before and after regulation. They collected data from a national sample of office-based physicians. The goal was to evaluate how policy changes influenced laboratory practices. They also aimed to determine if trained professionals affected quality outcomes. The study design allowed for comparison across four survey years. The findings were intended to inform future policy and practice standards.

The National Ambulatory Medical Care Survey was used to collect data from office-based physicians. Trained field representatives gathered clinical laboratory information via telephone. Surveys were conducted in 1989, 1991, 1993, and 1994. Each year's data came from a nationally representative sample of physicians. Weighted univariate and multivariate analyses were performed on responses. Researchers combined data from 1989 and 1991 as a pre-CLIA '88 group. They also combined 1993 and 1994 as a post-CLIA '88 group. The analysis focused on changes in quality indicators and professional involvement.

Quality indicators showed significant improvements between 1989 and 1994. Proficiency testing enrollment increased from 32.4% to 52.7% (P<.001). Daily quality control use rose from 79.2% to 89.0% (P<.001). Quality control with action steps increased from 62.6% to 77.2% (P<.001). These changes were linked to CLIA '88 implementation in 1992. The presence of a trained laboratory professional was associated with better quality. On-site testing decreased from 56% to 45% during the study period. Total testing volume remained stable despite this decline. The findings suggest regulation and expertise improved laboratory practices.

The study found that physician's office laboratory practices improved between 1989 and 1994. The CLIA '88 final rule played a key role in these changes. Quality indicators increased significantly after regulation implementation. Trained professionals were linked to better outcomes in all quality areas. The decrease in on-site testing did not affect overall testing volume. These findings suggest that minimum standards and professional involvement are important. The authors propose that policy changes can drive quality improvements. They suggest that continued monitoring is necessary to sustain these gains.