Validation of the mobile verbal learning test: Illustration of its use for age and disease-related cognitive deficits
INTERNATIONAL JOURNAL OF METHODS IN PSYCHIATRIC RESEARCH
Authors: Moore, Raeanne C.; Paolillo, Emily W.; Sundermann, Erin E.; Campbell, Laura M.; Delgadillo, Jeremy; Heaton, Anne; Swendsen, Joel; Depp, Colin A.
Abstract
Objective We developed a mobile cognitive test of verbal learning and memory, the mobile verbal learning test (mVLT), to allow for brief, repeated and portable delivery of a 12-item list learning test through a smartphone. This study examined the psychometric properties of the mVLT among older persons with and without human immunodeficiency virus (HIV). Methods Sixty-eight persons with HIV and 36 HIV-negative individuals (aged 50-74) completed three trials of the mVLT on a smartphone once daily for 14 days. A different word list was administered each day. Results Participants completed 80% of the 14 mVLT administrations, equating to 1166 valid and complete mVLTs. Neither adherence nor mean mVLT total score (number correct in 3 recall trials) differed by HIV status. No practice effects from repeated mVLT administration were observed, and there were moderately strong correlations of mVLT performance with performance on the in-lab version of the task and with traditional cognitive assessments of cognitive processes contributing to memory. We found evidence of within-person learning across mVLT trials, with persons with HIV demonstrating less learning from trials 1 to 3 compared to HIV-negative participants. Conclusions The mVLT is a valid method to assess learning in the real world in older adults with and without HIV.
Diagnostic accuracy of 3 urine lipoarabinomannan tuberculosis assays in HIV-negative outpatients
JOURNAL OF CLINICAL INVESTIGATION
Authors: Broger, Tobias; Nicol, Mark P.; Sigal, George B.; Gotuzzo, Eduardo; Zimmer, Alexandra J.; Surtie, Shireen; Caceres-Nakiche, Tatiana; Mantsoki, Anna; Reipold, Elena Ivanova; Szekely, Rita; Tsionsky, Michael; van Heerden, Judith; Plisova, Tatiana; Chikamatsu, Kinuyo; Lowary, Todd L.; Pinter, Abraham; Mitarai, Satoshi; Moreau, Emmanuel; Schumacher, Samuel G.; Denkinger, Claudia M.
Abstract
BACKGROUND. Inadequate tuberculosis (TB) diagnostics are a major hurdle in the reduction of disease burden, and accurate point-of-care tests (POCTs) are urgently needed. We assessed the diagnostic accuracy of Fujifilm SILVAMP TB lipoarabinomannan (FujiLAM) POCT for TB diagnosis in HIV-negative outpatients and compared it with Alere Determine TB LAM Ag (AlereLAM) POCT and a laboratory-based ultrasensitive electrochemiluminescence LAM research assay (EclLAM). METHODS. In this multicenter diagnostic test accuracy study, we recruited HIV-negative adults with symptoms suggestive of pulmonary TB presenting to outpatient health care centers in Peru and South Africa. Urine samples were tested using FujiLAM, AlereLAM, and EclLAM, and the diagnostic accuracy was assessed against a microbiological reference standard (MRS) and a composite reference standard. RESULTS. Three hundred seventy-two HIV-negative participants were included and the prevalence of microbiologically confirmed TB was 30 %. Compared with the MRS, the sensitivities of AlereLAM, FujiLAM, and EclLAM were 10.8% (95% confidence interval [CI] 6.3%-18.0%), 53.2% (95% CI 43.V%-62.1%), and 66.7% (95% CI 57.5%-74.7%), respectively. The specificities of AlereLAM, FujiLAM, and EcILAM were 92.3% (95% CI 88.5%-95.0%), 98.9% (95% CI 96.7%-99.6%), and 98.1% (95% CI 95.6%-99.2%), respectively. Positive likelihood ratios of AlereLAM, FujiLAM, and EclLAM were 1.4, 46.2, and 34.8, respectively, and positive predictive values were 37.5%, 95.2%, and 93.7%, respectively. CONCLUSION. Compared with AlereLAM, FujiLAM detected 5 times more patients with TB in HIV-negative participants, had a high positive predictive value, and has the potential to improve rapid diagnosis of TB at the point-of-care. EclLAM demonstrated that additional sensitivity gains are possible, which highlights LAM's potential as a biomarker. Additional research is required to assess FujiLAM's performance in prospective cohorts, its cost-effectiveness, and its impact in real-world clinical settings.