Nursing home (NH) care quality has long been a concern of general public, policymakers, and NH administrators because it directly impacts quality of life of the frail elderly. U.S. Federal and State governments oversight NH quality through the survey and certification process. There is a significant random variation in survey results across states attributed to measurement noise. Also, there is a numeric system to quantify the scope and severity of problems identified and cited per survey. The purpose of this study was to create a numeric system for measuring deficiency scope and severity and develop approaches for reducing measurement noise in survey results. A Delphi technique involving 10 NH quality experts was used to develop a numeric scope and severity score (SSS). Three metrics were proposed to quantify survey outcomes: Number of Health Deficiencies Adjusted (NHDA) indicates what facility number of health deficiencies (NHD) would be if it was located in a state with average NHD equal to the national average. Scope and Severity Index (SSI) indicates what facility SSS would be if it was located in a state with an average NHD equal to the national average. Scope and Severity Score Adjusted (SSSA) indicates what facility SSS would be if it was located in a state with an average SSS equal to the national average. Convergent validity of the proposed metrics against metrics of staffing, clinical quality, and denial of payment for new admissions was tested using Hierarchical Linear Modeling. All adjustments eliminated the noise almost completely. SSI was the only metric that retained state non-random variability. SSSA and NHDA had no variability across states by design. SSI and SSSA demonstrated better convergent validity than NHDA. NHD and SSS per citation were positively correlated. Conclusions. Adjustment for state effect is necessary to compare survey results across states. NH administrators, policymakers, and payers should use the SSI to compare NH performance across states.