Evaluation of an Upper Arm Capillary Blood Collection Device Compared with Venous and Fingerstick Sampling

Upper arm capillary blood collection devices may expand access to laboratory testing outside traditional phlebotomy settings. We evaluated the analytical performance and patient preference of the ImPress, an investigational-use upper arm capillary blood collection device compared with venous and fingerstick sampling.

Matched samples were collected from 43 healthy volunteers. Sixteen routine chemistry and lipid analytes were measured on standard laboratory platforms. Agreement was assessed using Deming regression and bias at medical decision points (MDPs), with acceptability defined by total allowable error (TEa). Hemolysis indices were compared across collection methods. Participants completed a survey.

A total of 315 specimens were analyzed. Thirteen of 16 analytes met predefined acceptance criteria for upper arm capillary compared with venous sampling. Mean bias at MDP ranged from -3.1% to 10% for venous vs upper arm capillary samples. Albumin, calcium, and aspartate aminotransferase (AST) did not meet acceptance criteria, primarily because all samples were within a tight normal range. All correlation coefficients (R, Deming regression) were ≥0.90, indicating linear relationships between collection modalities. Hemolysis indices for samples collected by the upper arm capillary device were well below assay interference thresholds. Mean pain scores (0 to 10 scale) were lowest for upper arm capillary (0.55) compared with venipuncture (2.61) and fingerstick (2.87). Most participants (74%) reported a preference for an upper arm capillary device.

Upper arm capillary blood collection demonstrated strong analytical agreement with venous and fingerstick sampling for most routine analytes, low clinically significant hemolysis, and high patient acceptability. These findings support its potential use in decentralized and remote laboratory testing.