Class | Variation in data entry | Effect on measures | Solutions to minimise distortion of measures |
Identification of ICU patients | CCU patients (PTS) were classified as cardiology treating specialty not as ICU PTS | CCU patients were not included in ICU cohort, Distorted image of ICU care | Add CCU to ICU treating specialty fields, scan each ICU quarterly for variation in proportion of major diagnoses benchmarked to type of ICU |
SICU PTS after discharge to medical step down unit electronically remained in SICU treating specialty (to track workload) | Treating specialty dates determined length of stay (LOS) in ICU, this prolonged SICU length of stay | Add surgical step down to treating specialty fields. Monitor with # patient days/maximal # days (>100% is impossible) | |
PTS in a step-down ward were assigned an ICU treating specialty | Artificial reduction in severity of illness in ICU cohort that included step-down patients | 1. Communicate with local ICU managers to validate each individual ward assigned to an ICU treating specialty. 2. Track quarterly variation by ICU in severity of illness | |
PTS were electronically moved out of the ICU location when ready for ward but physically remained in ICU when no acute care bed was available. | Artificial shortening or length of stay | 1. Use two sources to determine LOS, one with treating specialty, the other with ward location. Feedback differences to local leadership and managers | |
Duplicate deaths | PTS readmitted and died within 24 h of index hospital discharge may be counted dead twice. | Inflates risk adjusted and unadjusted mortality rates | Add screening for duplicate deaths |
Capture of medication orders | Medications orders are captured by dispensed status. Those meds dispensed from ward stock were invisible (subq heparin, insulin) | Underestimates adherence to deep venous prophylaxis, treatment for hyperglycemia | Revise extraction program |
Satellite pharmacies used different procedures for completing orders | Same | Use data from bar coded medication administration | |
Laboratory data location | Location of lab values varied across the country | In the risk model, a normal value is inserted for ‘unmeasured’ labs–could underestimate severity of illness, or adherence (proportion of patients with therapeutic INR on Coumadin) | Map initial laboratory value locations, track proportion of missing labs for each lab value for each quarterly report |
Change in lab value location occurs with addition of new reagents and new testing machines commonly | Developed system to allow identification of changes in the laboratory maps each quarter | ||
Laboratory normal values | Normal range of newer laboratory tests varies (ex. Troponin 10% coefficient of variation ranges from 0.03 to >5) | Inability to use laboratory test in risk model | Categorise data (troponin normal, high, abnormal) |
Determine lab test manufacturer quarterly | |||
Classify type of instrument (point of care) |
CCU, cardiac care unit; SICU, surgical care unit; ICU, intensive care unit; PTS, patients.