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Table 2 Demographic parameters compared

From: Quality of EHR data extractions for studies of preterm birth in a tertiary care center: guidelines for obtaining reliable data

  1. Manually abstracted database, # of subjects 2. EHR extract-ion, # of subjects 3. Discrepancy (% and # of subjects) between the databases a 4. Manually abstracted database errors 5. EHR-extracted data errors 6. Median discrepancy 7. Discrepancy range
Gestational age 1772 700 2.6 % (18) 1.0 % (7) 1.3 % (9) 1 week 1–10 weeks
Birthweight 1772 735 9.7 % (71) 1.5 % (11) 8.0 % (59) c **** 13 g 2–548 gm
Neonate race b 1758 1384 3.2 % (44) !- !- NA NA
Neonate ethnicity 1757 596 1.5 % (9) !- !- NA NA
Mother race b 1749 1378 3.2 % (45) !- !- NA NA
Mother ethnicity 1739 595 5.0 % (30) !- !- NA NA
  1. Demographic parameters compared in the paper. The denominator for the percentage is the smaller of the corresponding values in the first two columns
  2. ! – EHR manual review data could not be used as a gold standard – often recorded as unknown or null, while the manually collected data was based on patient interviews and was more detailed. *P0.05; **P0.01; ***P0.001; ****P0.0001
  3. a - In general, the sum of the error counts in columns 4 and 5 do not add up to the number in column 3, because the error occurred in both manually and electronically extracted data, or the cause was ambiguous
  4. b - Re-calculated discrepancies after adjusting for the inappropriate Hispanic category in the race column
  5. c - Difference statistically significant, p = 4.3 × 10−9 by Chi-square test