A Case for Unifying Accelerometry-Derived Movement Behaviors and Tests of Exercise Capacity for the Assessment of Relative Physical Activity Intensity.

Albert Einstein taught us that "everything is relative." People's experience of physical activity (PA) is no different, with "relativism" particularly pertinent to the perception of intensity. Markers of absolute and relative intensities of PA have different but complimentary utilities, with absolute intensity considered best for PA guideline adherence and relative intensity for personalized exercise prescription. Under the paradigm of exercise and PA as medicine, our Technical Note proposes a method of synchronizing accelerometry with the incremental shuttle walking test to facilitate description of the intensity of the free-living PA profile in absolute and relative terms. Our approach is able to generate and distinguish "can do" or "cannot do" (based on exercise capacity) and "does do" or "does not do" (based on relative intensity PA) classifications in a chronic respiratory disease population, facilitating the selection of potential appropriate individually tailored interventions. By synchronizing direct assessments of exercise capacity and PA, clearer insights into the intensity of PA performed during everyday life can be gleaned. We believe the next steps are as follows: (1) to determine the feasibility and effectiveness of using relative and absolute intensities in combination to personalize the approach, (2) to determine its sensitivity to change following interventions (eg, exercise-based rehabilitation), and (3) to explore the use of this approach in healthier populations and in other long-term conditions

Baseline characteristics.

<p>Data presented as N (%) or Median (IQR, inter-quartile range),</p>a<p>n = 177.</p

Effect of chlorhexidine - nystatin oral rinse on culture contamination.

p<p>N = 177, Total HIV positive participants;</p>q<p>n = 92,</p>r<p>n = 85.</p>s<p>N = 43, Total HIV negative participants;</p>t<p>n = 18,</p>u<p>n = 25.</p

Flow diagram summarizing enrolment and analysis results.

<p>Flow diagram summarizing enrolment and analysis results.</p

Study enrollment.

<p>Of 525 eligible patients, 477 (91%) were included in the study. 287 patients were enrolled during the initial baseline phase (Xpert MTB/RIF results not provided to clinicians during this validation phase) and 190 were enrolled during the implementation phase (Xpert MTB/RIF results provided to clinicians and used for patient management). Eighteen patients (nine in the baseline phase and nine in the implementation phase) died within three days of admission and were not included in survival analysis.</p

Survival of TB patients with all losses to follow-up censored: Baseline vs. Implementation phase.

<p>Kaplan-Meier survival curves are shown for TB patients enrolled during the baseline and implementation phases. There was no difference in two-month mortality by study phase for the 252 patients with culture-positive TB (17% vs. 14%, difference +3%, 95% CI: −21% to +27%, p = 0.80).</p

Outcomes in Baseline vs. Implementation phase.

<p><b><u>Abbreviations:</u></b> TB (tuberculosis).</p><p><b><u>Legend:</u></b> Sensitivity and specificity data are number correct/total (%) 95% CI.</p><p>Positive and negative predictive values are presented as % (95% CI).</p><p>Times are presented as medians (IQR).</p

Proportion of TB patients initiated on anti-TB therapy based on test, by study phase.

<p>The bars show the proportion of culture-positive TB patients in the baseline vs. the implementation phase started on anti-TB therapy based on rapid test results (<i>i.e.,</i> smear in baseline phase and smear/Xpert in implementation phase; 60% vs. 71%, p = 0.055), empirically prior to hospital discharge (15% vs. 7%, p = 0.047), or based on culture results (6% vs. 7%, p = 0.92). The proportion of patients with culture-confirmed TB who were never treated during this study period was similar (19% vs. 15%, p = 0.42).</p

Impact of Xpert MTB/RIF Testing on Tuberculosis Management and Outcomes in Hospitalized Patients in Uganda

<div><h3>Rationale</h3><p>The clinical impact of Xpert MTB/RIF for tuberculosis (TB) diagnosis in high HIV-prevalence settings is unknown.</p> <h3>Objective</h3><p>To determine the diagnostic accuracy and impact of Xpert MTB/RIF among high-risk TB suspects.</p> <h3>Methods</h3><p>We prospectively enrolled consecutive, hospitalized, Ugandan TB suspects in two phases: baseline phase in which Xpert MTB/RIF results were not reported to clinicians and an implementation phase in which results were reported. We determined the diagnostic accuracy of Xpert MTB/RIF in reference to culture (solid and liquid) and compared patient outcomes by study phase.</p> <h3>Results</h3><p>477 patients were included (baseline phase 287, implementation phase 190). Xpert MTB/RIF had high sensitivity (187/237, 79%, 95% CI: 73–84%) and specificity (190/199, 96%, 95% CI: 92–98%) for culture-positive TB overall, but sensitivity was lower (34/81, 42%, 95% CI: 31–54%) among smear-negative TB cases. Xpert MTB/RIF reduced median days-to-TB detection for all TB cases (1 [IQR 0–26] vs. 0 [IQR 0–1], p<0.001), and for smear-negative TB (35 [IQR 22–55] vs. 22 [IQR 0–33], p = 0.001). However, median days-to-TB treatment was similar for all TB cases (1 [IQR 0–5] vs. 0 [IQR 0–2], p = 0.06) and for smear-negative TB (7 [IQR 3–53] vs. 6 [IQR 1–61], p = 0.78). Two-month mortality was also similar between study phases among 252 TB cases (17% vs. 14%, difference +3%, 95% CI: −21% to +27%, p = 0.80), and among 87 smear-negative TB cases (28% vs. 22%, difference +6%, 95% CI: −34 to +46%, p = 0.77).</p> <h3>Conclusions</h3><p>Xpert MTB/RIF facilitated more accurate and earlier TB diagnosis, leading to a higher proportion of TB suspects with a confirmed TB diagnosis prior to hospital discharge in a high HIV/low MDR TB prevalence setting. However, our study did not detect a decrease in two-month mortality following implementation of Xpert MTB/RIF possibly because of insufficient powering, differences in empiric TB treatment rates, and disease severity between study phases.</p> </div

Survival of smear-negative TB patients with all losses to follow-up censored: Baseline vs. Implementation phase.

<p>Kaplan-Meier survival curves are shown for smear-negative TB patients enrolled during the baseline and implementation phases. There was no difference in two-month mortality by study phase for the 87 patients with smear-negative, culture-positive TB (28% vs. 22%, difference +6%, 95% CI: −34 to +46%, p = 0.77).</p