Table 2—

Agreement of diabetes diagnostic codes with patient survey, medication prescriptions, and HbA1c testing among 737,340 VA patients who completed a 1999 survey

% indicating diabetes in survey by diabetes diagnostic codes in prior 24 months*
Total number of codes
Number of codes in inpatient records
# of codes in outpatient records07.0%6.8%50.8%70.2%82.9%71.6%06.8%
Diagnostic codesPrevalence ratePositive predictive valueSpecificity§SensitivityPrior treatment and testing
Diabetes medicationHbA1c testing
Anyvalue of 7+value of 8+
Any OP21.7%85.8%95.9%77.5%70.2%68.7%37.4%24.4%
Any IP6.9%93.7%99.4%26.9%74.7%67.5%37.6%25.0%
2+OP or 1+IP18.9%92.8%98.1%73.7%77.6%72.8%41.0%26.8%
2+ any18.7%93.4%98.3%73.1%80.9%75.4%42.1%27.6%
2+ OP18.4%93.7%98.4%72.2%82.1%76.4%43.0%28.2%
3+ any17.3%95.2%98.9%69.0%84.4%77.8%44.5%29.3%
3+ OP17.0%95.4%98.9%68.0%85.3%78.6%45.2%29.7%
4+ any16.1%96.0%99.1%65.0%86.4%79.1%45.9%30.3%
4+ OP15.8%96.2%99.2%63.8%87.1%79.8%46.6%30.7%
  • *

    * Diagnostic codes from VA and Medicare records from 7/97 to 6/99;

  • diabetes medication prescriptions and HbA1c testing from 10/98 to 6/99;

  • those indicating diabetes in survey as a percent of those with specified diabetes diagnostic codes in row;

  • §

    § those without the specified diabetes diagnostic codes in row as a percent of those not indicating diabetes in survey;

  • those with specified diabetes diagnostic codes in row as a percent of those indicating diabetes in survey. OP, outpatient; IP, inpatient.