Using Discharge Abstracts to Evaluate a Regional Perinatal Network: Assessment of the Linkage Procedure of Anonymous Data

Table 3

Percentages of missing data for each identification item, among false negatives, for each year.

Years	Maiden name (%)	Mother’s first name (%)	Mother’s date of birth (%)	Infant’s first name (%)	Infant’s date of birth (%)	Zip code (%)
1998	95.33	97.40	97.40	91.14	90.98	0.32
1999	55.49	94.08	94.08	12.68	5.63	2.54
2000	62.62	67.91	69.28	20.94	16.05	25.24
2001	45.04	40.53	23.74	27.92	27.11	2.63
2002	58.22	27.40	29.47	34.47	19.30	1.03
2003	33.10	32.42	39.53	59.56	24.92	1.91
2004	27.46	25.66	11.85	38.80	30.85	0.63
2005	88.36	87.66	19.65	87.19	81.92	3.07
2006	74.96	74.46	71.97	47.43	32.34	1.00