Patient misidentification in laboratory medicine: a qualitative analysis of 227 root cause analysis reports in the Veterans Health Administration.

CONTEXT: Mislabeled laboratory specimens are a common source of harm to patients, such as repeat phlebotomy; repeat diagnostic procedure, including tissue biopsy; delay in a necessary surgical procedure; and the execution of an unnecessary surgical procedure. Mislabeling has been estimated to occur at a rate of 0.1% of all laboratory and anatomic pathology specimens submitted. OBJECTIVE: To identify system vulnerabilities in specimen collection, processing, analysis, and reporting associated with patient misidentification involving the clinical laboratory, anatomic pathology, and blood transfusion services. DESIGN: A qualitative analysis was performed on 227 root cause analysis reports from the Veterans Health Administration. Content analysis of case reports from March 9, 2000, to March 1, 2008, was facilitated by a Natural Language Processing program. Data were categorized by the 3 stages of the laboratory test cycle. RESULTS: Patient misidentification accounted for 182 of 253 adverse events, which occurred in all 3 stages of the test cycle. Of 132 misidentification events occurring in the preanalytic phase, events included wrist bands labeled for the wrong patient were applied on admission (n = 8), and laboratory tests were ordered for the wrong patient by selecting the wrong electronic medical record from a menu of similar names and Social Security numbers (n = 31). Specimen mislabeling during collection was associated with "batching" of specimens and printed labels (n = 35), misinformation from manual entry on laboratory forms (n = 14), failure of 2-source patient identification for clinical laboratory specimens (n = 24), and failure of 2-person verification of patient identity for blood bank specimens (n = 20). Of 37 events in the analytic phase, relabeling all specimens with accession numbers was associated with mislabeled specimen containers, tissue cassettes, and microscopic slides (n = 27). Misidentified microscopic slides were associated with a failure of 2-pathologist verification for cancer diagnosis (n = 4), and wrong patient transfusions were associated with mislabeled blood products (n = 3) and a failure of 2-person verification for blood products before release by the blood bank (n = 3). There were 13 events in the postanalytic phase in which results were reported into the wrong patient medical record (n = 8), and incompatible blood transfusions were associated with failed 2-person verification of blood products (n = 5). CONCLUSIONS: Patient misidentification in the clinical laboratory, anatomic pathology, and blood transfusion processes were due to a limited set of causal factors in all 3 phases of the test cycle. A focus on these factors will inform systemic mitigation and prevention strategies.

Skin distraction at select landmarks on the spine midline in the upright and fully flexed postures.

BACKGROUND: This study was aimed at quantifying superoinferior and mediolateral skin distraction over the spine's midline for the purpose of designing a unique surface marker for use in a study originally proposed by Wojtys and Ashton-Miller. It was also aimed at testing the null hypotheses H(01): There is no difference in the amount of skin distraction between hamstring normal and hamstring tight subjects and H(02): There are no age or gender differences of skin distraction. METHODS: Nine male and twelve female volunteers served as the convenience subjects for this IRB-approved study. Eight subjects were classified as hamstring "tight" (short) using the Finger-to-Floor Reach Test. Skin distraction was measured at five spine midline landmarks palpated on the subjects' bared backs: T1, T10, L3, S1, and the posterior-superior iliac spine (PSIS). A pattern of four dots was placed at each landmark using a rectangular template and non-toxic, water-soluble ink. Measurements were taken between superoinferior and mediolateral pairs of template points with subjects in both upright ("initial") and fully flexed ("final") postures. Between-measurement differences were then calculated, expressed as percent strain, and pooled for mean percent strain values. Repeated measures produced a maximum strain error of about 1.7%. RESULTS: With the exception of the skin over the T10 landmark, distraction in the superoinferior direction was greater than that in the mediolateral direction. There were no significant differences in skin distraction between age or gender groups. However, hamstring short males had significantly smaller superoinferior skin distraction at L3 than their hamstring normal counterparts [35% (+/-5.2) vs. 46% (+/-4.6), p=0.049), while hamstring short females had a smaller mean mediolateral distraction at the same level that approached significance [2.5% (+/-2.5) vs. 7.6% (+/-5.4), p=0.080). At this landmark, there was a moderately strong, inverse correlation (r=-0.720) between mediolateral percent strain and reach distance in hamstring tight subjects. CONCLUSION: In general, superoinferior percent strain increased and mediolateral percent strain decreased from thoracic to sacral regions, likely reflecting the relative increase in spine segment motion from thoracic to lumbar region. The larger mean mediolateral distraction at the T10 level was probably the result of traction on the skin at that level by the dependence of appendicular structures in forward flexion. Finally, the negative value at the T1 landmark was probably the result of the cervical spine extension that occurred during flexion as the subjects lifted their heads to look up.