Investigating the accuracy of blood oxygen saturation measurements in common consumer smartwatches.

Blood oxygen saturation (SpO2) is an important measurement for monitoring patients with acute and chronic conditions that are associated with low blood oxygen levels. While smartwatches may provide a new method for continuous and unobtrusive SpO2 monitoring, it is necessary to understand their accuracy and limitations to ensure that they are used in a fit-for-purpose manner. To determine whether the accuracy of and ability to take SpO2 measurements from consumer smartwatches is different by device type and/or by skin tone, our study recruited patients aged 18-85 years old, with and without chronic pulmonary disease, who were able to provide informed consent. The mean absolute error (MAE), mean directional error (MDE) and root mean squared error (RMSE) were used to evaluate the accuracy of the smartwatches as compared to a clinical grade pulse oximeter. The percent of data unobtainable due to inability of the smartwatch to record SpO2 (missingness) was used to evaluate the measurability of SpO2 from the smartwatches. Skin tones were quantified based on the Fitzpatrick (FP) scale and Individual Typology Angle (ITA), a continuous measure of skin tone. A total of 49 individuals (18 female) were enrolled and completed the study. Using a clinical-grade pulse oximeter as the reference standard, there were statistically significant differences in accuracy between devices, with Apple Watch Series 7 having measurements closest to the reference standard (MAE = 2.2%, MDE = -0.4%, RMSE = 2.9%) and the Garmin Venu 2s having measurements farthest from the reference standard (MAE = 5.8%, MDE = 5.5%, RMSE = 6.7%). There were also significant differences in measurability across devices, with the highest data presence from the Apple Watch Series 7 (88.9% of attempted measurements were successful) and the highest data missingness from the Withings ScanWatch (only 69.5% of attempted measurements were successful). The MAE, RMSE and missingness did not vary significantly across FP skin tone groups, however, there may be a relationship between FP skin tone and MDE (intercept = 0.04, beta coefficient = 0.47, p = 0.04). No statistically significant difference was found between skin tone as measured by ITA and MAE, MDE, RMSE or missingness.

Trachoma: an update on prevention, diagnosis, and treatment.

PURPOSE OF REVIEW: To review recent clinical and epidemiological studies regarding the prevention, diagnosis, and treatment of trachoma. RECENT FINDINGS: Newer studies propose novel diagnostic tests that appear sensitive for the detection of ocular chlamydial infection. For example, recent studies with ribosomal RNA-based nucleic acid amplification tests (NAATs) have demonstrated improved sensitivities compared to DNA-based NAATs; and the progression of scarring has now been characterized with confocal microscopy. Immunologic studies have further explored the etiology of clinical sequelae, suggesting that chronic inflammation can lead to progressive scarring even in the absence of Chlamydia. Mass oral azithromycin distributions remain a mainstay of treatment; studies have assessed the appropriate frequency and duration of treatment programs. Current studies have also explored ancillary effects of azithromycin distribution on mortality and bacterial infections. SUMMARY: Trachoma programs have had remarkable success at reducing chlamydial infection and clinical signs of trachoma. Recent work suggests improved methods to monitor infection and scarring, and better ways to distribute treatment. Whereas studies continue to demonstrate reduction in infection in hyperendemic areas, more work is necessary to achieve elimination of this blinding disease.

Association of Dry Eye Tests With Extraocular Signs Among 3514 Participants in the Sjögren's Syndrome International Registry.

PURPOSE: To identify a screening strategy for dry eye patients with a high likelihood of having Sjogren syndrome (SS) through the evaluation of the association of ocular surface tests with the extraocular signs used for the diagnosis of SS. DESIGN: Multicenter cross-sectional study. METHODS: The Sjogren's International Clinical Collaborative Alliance (SICCA) registry enrolled 3514 participants with SS or possible SS from 9 international academic sites. Ocular surface evaluation included Schirmer I testing, tear breakup time (TBUT), and staining of the cornea (0-6 points) and conjunctiva (0-6 points). Multivariate logistic regression analysis was performed to identify predictive factors for (1) histopathologic changes on labial salivary gland (LSG) biopsies (positive = focus score of ≥1 focus/4 mm2) and (2) positive anti-SSA/B serology. RESULTS: The adjusted odds of having a positive LSG biopsy were significantly higher among those with an abnormal Schirmer I test (adjusted OR = 1.26, 95% CI 1.05-1.51, P = .014) and positive conjunctival staining (for each additional unit of staining 1.46; 95% CI 1.39-1.53, P < .001) or corneal staining (for each additional unit of staining 1.14; 95% CI 1.08-1.21, P < .001). The odds of having a positive serology were significantly higher among those with an abnormal Schirmer I test (adjusted OR = 1.3; 95% CI 1.09-1.54, P = .004) and conjunctival staining (adjusted OR = 1.51; 95% CI 1.43-1.58, P < .001). CONCLUSIONS: In addition to corneal staining, which was associated with a higher likelihood of having a positive LSG biopsy, conjunctival staining and abnormal Schirmer I testing are of critical importance to include when screening dry eye patients for possible SS, as they were associated with a higher likelihood of having a positive LSG biopsy and serology.

Factors affecting patient access in Thailand: understanding delay in care seeking for patients with cancer.

While nearly three-quarters of cancer mortalities occur in low- and middle-income countries, we know little about the factors contributing to patient delays in seeking care for cancer. Our study employs a multifactorial approach by examining three key areas: patient socio-demographic factors, structural factors of health-care access and cancer patients' beliefs about their illness and cancer in general as potential determinants of their delay in seeking care in Thailand. We conducted a cross-sectional study using a systematic sample of 264 patients with cancer treated during 2006-2007 at Prince Maha Vajiralongkorn Cancer Centre, a hospital of the National Cancer Institute of Thailand. We defined patient delay as when a patient waited more than 3 months after symptom onset to seek medical care. We used bivariate analysis and multivariate logistic regression to examine unadjusted and adjusted associations of patient delays in seeking care with: patient socio-demographic factors, structural factors of health-care access and patients' beliefs about their illness in particular and about cancer in general. We also obtained patient self-reports about their reasons for delaying care. In multivariate analysis, only patient-belief factors were significantly associated with delay. Patients who believed that the primary causes of cancer were non-medical (vs. medical) were more likely to delay seeking care (adjusted odds ratio (OR)=4.37, 95% confidence interval (CI)=2.27-8.67). Patients who believed that cancer was probably curable or was curable (vs. incurable) were significantly less likely to delay seeking care (adjusted OR=0.2, 95% CI=0.08-0.56; adjusted OR=0.18, 95% CI=0.07-0.49, respectively). Patient socio-demographic factors and structural factors of health-care access were not significantly associated (p>0.05). Our findings suggest that interventions to reduce delays in care seeking should address patient beliefs regarding cancer in order to effectively mitigate barriers to access.