Table 2.
Sensitivity of Medicare Inpatient Claims to Identify Myocardial Infarctions Identified and Adjudicated Through REasons for Geographic And Racial Differences in Stroke Study Procedures.
| Medicare claims with a discharge diagnosis code for MI | |||||||
|---|---|---|---|---|---|---|---|
| Any position | Primary position | ||||||
| Characteristics | Total MIs* | n | Sensitivity (95% CI) | p-value† | n | Sensitivity (95% CI) | p-value† |
| Full population | 596 | 292 | 49.0 (44.9–53.1) | 239 | 40.1 (36.1–44.2) | ||
| Age | |||||||
| <75 years | 350 | 173 | 49.4 (44.1–54.8) | 0.80 | 143 | 40.9 (35.7–46.2) | 0.65 |
| ≥75 years | 246 | 119 | 48.4 (42.0–54.8) | 96 | 39.0 (32.9–45.4) | ||
| Sex | |||||||
| Women | 205 | 113 | 55.1 (48.0–62.1) | 0.03 | 92 | 44.9 (37.9–52.0) | 0.08 |
| Men | 391 | 179 | 45.8 (40.8–50.9) | 147 | 37.6 (32.8–42.6) | ||
| Race | |||||||
| White | 433 | 217 | 50.1 (45.3–54.9) | 0.37 | 184 | 42.5 (37.8–47.3) | 0.05 |
| Black | 163 | 75 | 46.0 (38.2–54.0) | 55 | 33.7 (26.5–41.6) | ||
| Geographic region of residence‡ | |||||||
| Stroke buckle | 142 | 70 | 49.3 (40.8–57.8) | (ref) | 59 | 41.5 (33.3–50.1) | (ref) |
| Stroke belt | 220 | 108 | 49.1 (42.3–55.9) | 0.97 | 89 | 40.5 (33.9–47.3) | 0.84 |
| Other contiguous US states | 234 | 114 | 48.7 (42.2–55.3) | 0.91 | 91 | 38.9 (32.6–45.5) | 0.61 |
| Calendar year | |||||||
| 2003–2006 | 186 | 86 | 46.2 (38.9–53.7) | (ref) | 70 | 37.6 (30.7–45.0) | (ref) |
| 2007–2009 | 238 | 116 | 48.7 (42.2–55.3) | 0.61 | 94 | 39.5 (33.2–46.0) | 0.70 |
| 2010–2012 | 172 | 90 | 52.3 (44.6–60.0) | 0.25 | 75 | 43.6 (36.1–51.4) | 0.25 |
| Education | |||||||
| Less than high school | 102 | 54 | 52.9 (42.8–62.9) | 0.38 | 41 | 40.2 (30.6–50.4) | 0.98 |
| High school or higher | 492 | 237 | 48.2 (43.7–52.7) | 197 | 40.0 (35.7–44.5) | ||
| Total annual household income | |||||||
| <$25,000 | 178 | 95 | 53.4 (45.8–60.9) | 0.08 | 76 | 42.7 (35.3–50.3) | 0.29 |
| ≥$25,000 | 351 | 159 | 45.3 (40.0–50.7) | 133 | 37.9 (32.8–43.2) | ||
| Cognitive impairment | |||||||
| No | 381 | 191 | 50.1 (45.0–55.3) | 0.27 | 160 | 42.0 (37.0–47.1) | 0.55 |
| Yes | 48 | 20 | 41.7 (27.6–56.8) | 18 | 37.5 (24.0–52.6) | ||
| History of CHD | |||||||
| No | 303 | 165 | 54.5 (48.7–60.2) | 0.005 | 139 | 45.9 (40.2–51.7) | 0.002 |
| Yes | 284 | 122 | 43.0 (37.1–48.9) | 95 | 33.5 (28.0–39.3) | ||
| Peak troponin level§ | |||||||
| <0.5 μg/L (microsize MI) | 183 | 25 | 13.7 (9.0–19.5) | <0.001 | 17 | 9.3 (5.5–14.5) | <0.001 |
| ≥0.5 μg/L | 405 | 262 | 64.7 (59.8–69.3) | 218 | 53.8 (48.8–58.8) | ||
| MI type|| | |||||||
| Type 1 MIs | 256 | 196 | 76.6 (70.9–81.6) | (ref) | 183 | 71.5 (65.5–76.9) | (ref) |
| Type 2 MIs | 288 | 89 | 30.9 (25.6–36.6) | <0.001 | 52 | 18.1 (13.8–23.0) | <0.001 |
| Type 3 MIs | 4 | 2 | 50.0 (6.8–93.2) | 0.24** | 1 | 25.0 (0.6–80.6) | 0.08** |
| Type 4–5 MIs | 45 | 5 | 11.1 (3.7–24.1) | <0.001 | 3 | 6.7 (1.4–18.3) | <0.001** |
| Place of occurrence | |||||||
| In-hospital | 278 | 80 | 28.8 (23.5–34.5) | (ref) | 43 | 15.5 (11.4–20.3) | (ref) |
| Out-of-hospital | 318 | 212 | 66.7 (61.2–71.8) | <0.001 | 196 | 61.6 (56.0–67.0) | <0.001 |
Abbreviations: CHD, coronary heart disease; CI, confidence interval; MI, myocardial infarction; ref, reference.
Definite or probable myocardial infarctions identified and adjudicated through REasons for Geographic And Racial Differences in Stroke study procedures.
P-values were calculated using a χ2 test, unless otherwise indicated.
Stroke buckle includes coastal plains of North Carolina, South Carolina and Georgia. Stroke belt includes the remaining parts of North Carolina, South Carolina and Georgia, and Tennessee, Mississippi, Alabama, Louisiana and Arkansas. Other contiguous US states includes the remaining 40 contiguous US states and the District of Columbia.
There are 8 MIs with missing peak troponin level.
There are 3 MIs with missing MI type.
Calculated using the Fisher’s exact test