Human papillomavirus (HPV) primary screening is an effective approach to assessing cervical cancer risk. Self-collected vaginal swabs can expand testing access, but the data de fi ning analytical performance criteria necessary for adoption of self-collected specimens are limited, especially for those occurring outside the clinic, where the swab remains dry during transport. Here, we evaluated the performance of self-collected vaginal swabs for HPV detection using the Cobas 6800. There was insigni fi cant variability between swabs self-collected by the same individual ( n = 15 participants collecting 5 swabs per participant), measured by ampli fi cation of HPV and human 13-globin control DNA. Comparison of self-collected vaginal swab and provider-collected cervical samples ( n = 144 pairs) proved highly concordant for HPV detection (total agreement = 90.3%; positive percentage agreement = 84.2%). There was no relationship between the number of dry storage days and amplifi cation of HPV ( n = 68; range, 4 to 41 days). Exposure of self-collected dry swabs to extreme summer and winter temperatures did not affect testing outcomes. A second internal control (RNase P) demonstrated that lack of ampli fi cation for 13-globin from self-collected specimens was consistent with poor, but not absent, cellularity. These data suggest that self-collected vaginal samples enable accurate clinical HPV testing, and that extended ambient dry storage or exposure to extreme temperatures does not in fl uence HPV detection. Furthermore, lack of 13-globin ampli fi cation in HPV-negative samples accurately identi fi ed participants who required recollection.
Direct access testing (DAT) is an emerging care model that provides on-demand laboratory services for certain preventative, diagnostic, and monitoring indications. Unlike conventional testing models where health care providers order tests and where sample collection is performed onsite at the clinic or laboratory, most interactions between DAT consumers and the laboratory are virtual. Tests are ordered and results delivered online, and specimens are frequently self-collected at home with virtual support. Thus, DAT depends on high-quality information technology (IT) tools and optimized data utilization to a greater degree than conventional laboratory testing. This review critically discusses the United States DAT landscape in relation to IT to highlight digital challenges and opportunities for consumers, health care systems, providers, and laboratories. DAT offers consumers increased autonomy over the testing experience, cost, and data sharing, but the current capacity to integrate DAT as a care option into the conventional patient-provider model is lacking and will require innovative approaches to accommodate. Likewise, both consumers and health care providers need transparent information about the quality of DAT laboratories and clinical decision support to optimize appropriate use of DAT as a part of comprehensive care. Interoperability barriers will require intentional approaches to integrating DAT-derived data into the electronic health records of health systems nationally. This includes ensuring the laboratory results are appropriately captured for downstream data analytic pipelines that are used to satisfy population health and research needs. Despite the data- and IT-related challenges for widespread incorporation of DAT into routine health care, DAT has the potential to improve health equity by providing versatile, discreet, and affordable testing options for patients who have been marginalized by the current limitations of health care delivery in the United States.
BACKGROUND:Urine albumin-to-creatinine ratio (uACR) is a screening assay for chronic kidney disease (CKD). A value of >30 mg/g is flagged abnormal, but lower ratios have prognostic implications. Thus, to maximize diagnostic utility, urine albumin (uAlb) should be measurable to 3 mg/L to match the lowest creatinine concentration generally utilized (10 mg/dL). Most uAlb assays have lower limits of quantitation (LLOQs) 2- to 4-fold higher. We sought to determine the performance characteristics of a commonly used uAlb assay at 3 mg/L and to evaluate the clinical screening impact of reducing the LLOQ. METHODS:Urine was serially diluted to assess uAlb linearity and precision for concentrations near the claimed LLOQ (12 mg/L). Samples (n = 30) with uAlb <12 mg/L were compared between laboratories. Sequential samples (n = 1239) were evaluated for clinical impact of reducing the measuring range to 3 mg/L. RESULTS:The assay was linear to 1.6 mg/L. Interday precision at 3.7 mg/L and 4.3 mg/L was 7.7% and 8.6%, respectively. Minimal bias was observed between labs (y = 1.091x - 0.75; average bias = -0.13 mg/L). Clinical validation demonstrated 501 of 1239 samples (40.4%) had uAlb <12 mg/L. Using 11.9 mg/L as the numerator for samples with uAlb <12 mg/dL and urine creatinine >10 mg/L, 107 of 499 (21.4%) would have a ratio flagged abnormal at >30 mg/g. Using the numeric value for these samples to 3 mg/L reduced alarm to <1%. CONCLUSIONS:A uAlb LLOQ of 3 mg/L improves screening utility of uACR by simplifying reporting and clinical interpretation when uAlb is low and provides clinical information for prognostic tools developed for people at risk of CKD.