Last data update: May 13, 2024. (Total: 46773 publications since 2009)
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Query Trace: Boer K[original query] |
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HIV-1 incidence, adherence, and drug resistance in individuals taking daily emtricitabine/tenofovir disoproxil fumarate for HIV-1 pre-exposure prophylaxis: Pooled analysis from 72 global studies
Landovitz RJ , Tao L , Yang J , de Boer M , Carter C , Das M , Baeten JM , Liu A , Hoover KW , Celum C , Grinsztejn B , Morris S , Wheeler DP , Mayer KH , Golub SA , Bekker LG , Diabaté S , Hoornenborg E , Myers J , Leech AA , McCormack S , Chan PA , Sweat M , Matthews LT , Grant R . Clin Infect Dis 2024 BACKGROUND: Oral pre-exposure prophylaxis (PrEP) with emtricitabine/tenofovir disoproxil fumarate (F/TDF) has high efficacy against HIV-1 acquisition. Seventy-two prospective studies of daily oral F/TDF PrEP were conducted to evaluate HIV-1 incidence, drug resistance, adherence, and bone and renal safety in diverse settings. METHODS: HIV-1 incidence was calculated from incident HIV-1 diagnoses after PrEP initiation and within 60 days of discontinuation. Tenofovir concentration in dried blood spots (DBS), drug resistance, and bone/renal safety indicators were evaluated in a subset of studies. RESULTS: Among 17,274 participants, there were 101 cases with new HIV-1 diagnosis (0.77 per 100 person-years; 95% CI 0.63-0.94). In 78 cases with resistance data, 18 (23%) had M184I or V, one (1.3%) had K65R, and three (3.8%) had both mutations. In 54 cases with tenofovir concentration data from DBS, 45 (83.3%), 2 (3.7%), 6 (11.1%), and 1 (1.9%) had average adherence of <2, 2-3, 4-6, and ≥7 doses/week, respectively, and the corresponding incidence was 3.9 (95% CI 2.9-5.3), 0.24 (0.060-0.95), 0.27 (0.12-0.60), and 0.054 (0.008-0.38) per 100 person-years. Adherence was low in younger participants, Hispanic/Latinx and Black participants, cisgender women, and transgender women. Bone and renal adverse event incidence rates were 0.69 and 11.8 per 100 person-years, respectively, consistent with previous reports. CONCLUSIONS: Leveraging the largest pooled analysis of global PrEP studies to date, we demonstrate that F/TDF is safe and highly effective, even with less than daily dosing, in diverse clinical settings, geographies, populations, and routes of HIV-1 exposure. |
HIV preexposure prophylaxis with emtricitabine and tenofovir disoproxil fumarate among cisgender women
Marrazzo J , Tao L , Becker M , Leech AA , Taylor AW , Ussery F , Kiragu M , Reza-Paul S , Myers J , Bekker LG , Yang J , Carter C , de Boer M , Das M , Baeten JM , Celum C . Jama 2024 IMPORTANCE: Emtricitabine and tenofovir disoproxil fumarate (F/TDF) for HIV preexposure prophylaxis (PrEP) is highly effective in cisgender men who have sex with men (MSM) when adherence is high (>4 doses/week). Real-world effectiveness and adherence with F/TDF for PrEP in cisgender women is less well characterized. OBJECTIVE: To characterize the effectiveness of F/TDF for PrEP and its relationship with adherence in cisgender women. DESIGN, SETTING, AND PARTICIPANTS: Data were pooled from 11 F/TDF PrEP postapproval studies conducted in 6 countries that included 6296 cisgender women aged 15 to 69 years conducted from 2012 to 2020. HIV incidence was evaluated according to adherence level measured objectively (tenofovir diphosphate concentration in dried blood spots or tenofovir concentration in plasma; n = 288) and subjectively (electronic pill cap monitoring, pill counts, self-report, and study-reported adherence scale; n = 2954) using group-based trajectory modeling. EXPOSURES: F/TDF prescribed orally once a day. HIV incidence was analyzed in subgroups based on adherence trajectory. MAIN OUTCOMES AND MEASURES: HIV incidence. RESULTS: Of the 6296 participants, 46% were from Kenya, 28% were from South Africa, 21% were from India, 2.9% were from Uganda, 1.6% were from Botswana, and 0.8% were from the US. The mean (SD) age at PrEP initiation across all studies was 25 (7) years, with 61% of participants being younger than 25 years. The overall HIV incidence was 0.72 per 100 person-years (95% CI, 0.51-1.01; 32 incident HIV diagnoses among 6296 participants). Four distinct groups of adherence trajectories were identified: consistently daily (7 doses/week), consistently high (4-6 doses/week), high but declining (from a mean of 4-6 doses/week and then declining), and consistently low (less than 2 doses/week). None of the 498 women with consistently daily adherence acquired HIV. Only 1 of the 658 women with consistently high adherence acquired HIV (incidence rate, 0.13/100 person-years [95% CI, 0.02-0.92]). The incidence rate was 0.49 per 100 person-years (95% CI, 0.22-1.08) in the high but declining adherence group (n = 1166) and 1.27 per 100 person-years (95% CI, 0.53-3.04) in the consistently low adherence group (n = 632). CONCLUSIONS AND RELEVANCE: In a pooled analysis of 11 postapproval studies of F/TDF for PrEP among cisgender women, overall HIV incidence was 0.72 per 100 person-years; individuals with consistently daily or consistently high adherence (4-6 doses/week) to PrEP experienced very low HIV incidence. |
Glycoprotein acetyls associate with intraglomerular hemodynamic dysfunction, albuminuria, central adiposity, and insulin resistance in youth with type 1 diabetes
McGee AC , Reinicke T , Carrasco D , Goodrich J , Pavkov ME , van Raalte D , Birznieks C , Nelson RG , Nadeau KJ , Choi YJ , Vigers T , Pyle L , de Boer I , Bjornstad P , Tommerdahl KL . Can J Diabetes 2024 AIMS: Glycoprotein acetyls (GlycA) is a biomarker of systemic inflammation and cardiovascular disease, yet little is known about its role in type 1 diabetes (T1D). We examined the associations among GlycA, central adiposity, insulin resistance, and early kidney injury in youth with T1D. METHODS: Glomerular filtration rate (GFR) and renal plasma flow (RPF) by iohexol and p-aminohippurate clearance, urine albumin-to-creatinine ratio (UACR), central adiposity by DXA, and estimated insulin sensitivity were assessed in fifty youth with T1D (16±3.0 years, 50% female, HbA(1c) 8.7±1.3%, T1D duration 5.7±2.6 years). Concentrations of GlycA were quantified by targeted nuclear magnetic resonance spectroscopy. Correlation and multivariable linear regression analyses were performed. RESULTS: GlycA was higher in girls vs. boys (1.05±0.26 vs. 0.84±0.15 mmol/L, p=0.001) and in participants who were overweight/obese vs. normal weight (1.12±0.23 vs. 0.87±0.20 mmol/L, p=0.0004). GlycA correlated positively with estimated intraglomerular pressure (r=0.52, p=0.001), UACR (r=0.53, p<0.0001) and trunk mass (r=0.45, p=0.001), and inversely with estimated insulin sensitivity (r:-0.36, p=0.01). All relationships remained significant after adjustment for age, sex, and HbA(1c). CONCLUSION: GlycA, a biomarker of inflammation, was higher in girls and those of overweight or obese body habitus in T1D. Additionally, GlycA associated with parameters of early kidney dysfunction, central adiposity, and insulin resistance. |
Triglyceride content of lipoprotein subclasses and kidney hemodynamic function and injury in adolescents with type 1 diabetes
Pauley ME , Vinovskis C , MacDonald A , Baca M , Pyle L , Wadwa RP , Fornoni A , Nadeau KJ , Pavkov M , Nelson RG , Gordin D , de Boer IH , Tommerdahl KL , Bjornstad P . J Diabetes Complications 2022 37 (2) 108384 AIMS: Elevated triglycerides (TG) are associated with development and progression of kidney disease, and TG distributions across lipoprotein subclasses predict kidney dysfunction in adults with type 1 diabetes (T1D). Little is known regarding these relationships in youth. METHODS: In this single center study conducted from October 2018-2019, lipid constituents from lipoprotein subclasses were quantified by targeted nuclear magnetic resonance spectroscopy. Glomerular filtration rate (GFR), renal plasma flow (RPF), afferent arteriolar resistance (R(A)), efferent arteriolar resistance (R(E)), intraglomerular pressure (P(GLO)), urine albumin-to-creatinine ratio (UACR), and chitinase-3-like protein 1 (YKL-40), a marker of kidney tubule injury, were assessed. Cross-sectional relationships were assessed by correlation and multivariable linear regression (adjusted for age, sex, HbA1c) models. RESULTS: Fifty youth with T1D (age 16 ± 3 years, 50 % female, HbA1c 8.7 ± 1.3 %, T1D duration 5.7 ± 2.6 years) were included. Very-low-density lipoprotein (VLDL)-TG concentrations correlated and associated with intraglomerular hemodynamic function markers including GFR, P(GLO), UACR, as did small low-density lipoprotein (LDL)-TG and small high-density lipoprotein (HDL)-TG. YKL-40 correlated with all lipoprotein subclasses. CONCLUSION: TG within lipoprotein subclasses, particularly VLDL, associated with P(GLO,) GFR, albuminuria, and YKL-40. Lipid perturbations may serve as novel targets to mitigate early kidney disease. |
Variant APOL1 protein in plasma associates with larger particles in humans and mouse models of kidney injury.
Andrews M , Yoshida T , Henderson CM , Pflaum H , McGregor A , Lieberman JA , de Boer IH , Vaisar T , Himmelfarb J , Kestenbaum B , Chung JY , Hewitt SM , Santo BA , Ginley B , Sarder P , Rosenberg AZ , Murakami T , Kopp JB , Kuklenyik Z , Hoofnagle AN . PLoS One 2022 17 (10) e0276649 BACKGROUND: Genetic variants in apolipoprotein L1 (APOL1), a protein that protects humans from infection with African trypanosomes, explain a substantial proportion of the excess risk of chronic kidney disease affecting individuals with sub-Saharan ancestry. The mechanisms by which risk variants damage kidney cells remain incompletely understood. In preclinical models, APOL1 expressed in podocytes can lead to significant kidney injury. In humans, studies in kidney transplant suggest that the effects of APOL1 variants are predominantly driven by donor genotype. Less attention has been paid to a possible role for circulating APOL1 in kidney injury. METHODS: Using liquid chromatography-tandem mass spectrometry, the concentrations of APOL1 were measured in plasma and urine from participants in the Seattle Kidney Study. Asymmetric flow field-flow fractionation was used to evaluate the size of APOL1-containing lipoprotein particles in plasma. Transgenic mice that express wild-type or risk variant APOL1 from an albumin promoter were treated to cause kidney injury and evaluated for renal disease and pathology. RESULTS: In human participants, urine concentrations of APOL1 were correlated with plasma concentrations and reduced kidney function. Risk variant APOL1 was enriched in larger particles. In mice, circulating risk variant APOL1-G1 promoted kidney damage and reduced podocyte density without renal expression of APOL1. CONCLUSIONS: These results suggest that plasma APOL1 is dynamic and contributes to the progression of kidney disease in humans, which may have implications for treatment of APOL1-associated kidney disease and for kidney transplantation. |
LED area lighting to reduce glare for roof bolter operators
Sammarco JJ , Mayton AG , Rubinstein EN . Min Metall Explor 2020 37 (3) 851-860 Researchers from the National Institute for Occupational Safety and Health (NIOSH) developed a light-emitting diode (LED) area luminaire called the Saturn and conducted a laboratory study using a Fletcher High Dual-boom Mast Feed (HDDR) roof bolting machine. The Saturn luminaire was designed to (1) enhance floor illumination to enable better detection of trip hazards in the interior spaces of a roof bolter and (2) reduce glare that has typically been an issue of concern on roof bolters. This paper reports on the results of achieving the second objective. The existing roof bolter lighting was the baseline and was compared with three versions of the Saturn luminaire relative to light intensity (100%, 75%, and 50%). Discomfort and disability glare data were obtained from 30 participants that comprised three age groups. Discomfort glare perceptions were obtained using the De Boer rating scale, and disability glare was quantified by using Mars Letter Contrast Sensitivity tests. Discomfort glare was reduced at least 3 levels with all Saturn versions. Also, a predictive model was used to estimate discomfort glare, and the results were similar. Disability glare was the least for the Saturn’s 50% intensity, and all Saturn versions had significantly less disability glare than with the baseline lighting. Veiling luminance was calculated and used as another indicator of disability glare. Veiling luminance was 28 to 42 times greater with the baseline lighting as compared with that of the Saturn lighting. Lastly, visibility levels were calculated. The Saturn versions were 4 to 6.5 times better in terms of visibility level. |
Validity of predictive equations for 24-h urinary potassium excretion based on timing of spot urine collection among adults: The MESA and CARDIA Urinary Sodium Study and NHANES Urinary Sodium Calibration Study
Mercado CI , Cogswell ME , Loria CM , Liu K , Allen N , Gillespie C , Wang CY , De Boer IH , Wright J . Am J Clin Nutr 2018 108 (3) 532-547 Background: 24-h urine collections are the suggested method to measure daily urinary potassium excretion (uK) but are costly and burdensome to implement. Objective: This study tested how well existing equations with the use of spot urine samples can estimate 24-h uK and if accuracy varies by timing of spot urine collection, age, race, or sex. Design: This cross-sectional study used data from 407 participants aged 18-39 y from the Washington, DC area in 2011 and 554 participants aged 45-79 y from Chicago in 2013. Spot urine samples were collected in individual containers for 24 h, and 1 for each timed period (morning, afternoon, evening, and overnight) was selected. For each selected timed spot urine, 24-h uK was predicted through the use of published equations. Difference (bias) between predicted and measured 24-h uK was calculated for each timed period and within age, race, and sex subgroups. Individual-level differences were assessed through the use of Bland-Altman plots and correlation tests. Results: For all equations, regardless of the timing of spot urine, mean bias was usually significantly different than 0. No one prediction equation was unbiased across all sex, race, and age subgroups. With the use of the Kawasaki and Tanaka equations, 24-h uK was overestimated at low levels and underestimated at high levels, whereas observed differential bias with the Mage equation was in the opposite direction. Depending on prediction equation and timing of urine sample, 61-75% of individual 24-h uKs were misclassified among 500-mg incremental categories from <1500 to ≥3000 mg. Correlations between predicted and measured 24-h uK were poor to moderate (0.19-0.71). Conclusion: Because predicted 24-h uK accuracy varies by timing of spot urine collection, published prediction equations, and within age-race-sex subgroups, study results making use of predicted 24-h uK in association with health outcomes should be interpreted with caution. It is possible that a more accurate prediction equation can be developed leading to different results. |
Fertility and HIV following universal access to ART in Rwanda: a cross-sectional analysis of demographic and health survey data
Remera E , Boer K , Umuhoza SM , Hedt-Gauthier BL , Thomson DR , Ndimubanzi P , Kayirangwa E , Mutsinzi S , Bayingana A , Mugwaneza P , Koama JB . Reprod Health 2017 14 (1) 40 BACKGROUND: HIV infection is linked to decreased fertility and fertility desires in sub-Saharan Africa due to biological and social factors. We investigate the relationship between HIV infection and fertility or fertility desires in the context of universal access to antiretroviral therapy introduced in 2004 in Rwanda. METHODS: We used data from 3532 and 4527 women aged 20-49 from the 2005 and 2010 Rwandan Demographic and Health Surveys (RDHS), respectively. The RDHSs included blood-tests for HIV, as well as detailed interviews about fertility, demographic and behavioral outcomes. In both years, multiple logistic regression was used to assess the association between HIV and fertility outcomes within three age categories (20-29, 30-39 and 40-49 years), controlling for confounders and compensating for the complex survey design. RESULTS: In 2010, we did not find a difference in the odds of pregnancy in the last 5 years between HIV-seropositive and HIV-seronegative women after controlling for potential biological and social confounders. Controlling for the same confounders, we found that HIV-seropositive women under age 40 were less likely to desire more children compared to HIV-seronegative women (20-29 years adjusted odds ratio (AOR) = 0.31, 95% CI: 0.17, 0.58; 30-39 years AOR = 0.24, 95% CI: 0.14, 0.43), but no difference was found among women aged 40 or older. No associations between HIV and fertility or fertility desire were found in 2005. CONCLUSIONS: These findings suggest no difference in births or current pregnancy among HIV-seropositive and HIV-seronegative women. That in 2010 HIV-seropositive women in their earlier childbearing years desired fewer children than HIV-seronegative women could suggest more women with HIV survived; and stigma, fear of transmitting HIV, or realism about living with HIV and prematurely dying from HIV may affect their desire to have children. These findings emphasize the importance of delivering appropriate information about pregnancy and childbearing to HIV-infected women, enabling women living with HIV to make informed decisions about their reproductive life. |
High HIV prevalence and associated risk factors among female sex workers in Rwanda
Mutagoma M , Samuel MS , Kayitesi C , Gasasira AR , Chitou B , Boer K , Hedt-Gauthier B , Gupta N , Ntaganira J , Nsanzimana S . Int J STD AIDS 2017 28 (11) 956462416688137 Human immunodeficiency virus (HIV) prevalence is often high among female sex workers (FSWs) in sub-Saharan Africa. Understanding the dynamics of HIV infection in this key population is critical to developing appropriate prevention strategies. We aimed to describe the prevalence and associated risk factors among a sample of FSWs in Rwanda from a survey conducted in 2010. A cross-sectional biological and behavioral survey was conducted among FSWs in Rwanda. Time-location sampling was used for participant recruitment from 4 to 18 February 2010. HIV testing was done using HIV rapid diagnostic tests (RDT) as per Rwandan national guidelines at the time of the survey. Elisa tests were simultaneously done on all samples tested HIV-positive on RDT. Proportions were used for sample description; multivariable logistic regression model was performed to analyze factors associated with HIV infection. Of 1338 women included in the study, 1112 consented to HIV testing, and the overall HIV prevalence was 51.0%. Sixty percent had been engaged in sex work for less than five years and 80% were street based. In multivariable logistic regression, HIV prevalence was higher in FSWs 25 years or older (adjusted odds ratio [aOR] = 1.83, 95% [confidence interval (CI): 1.42-2.37]), FSWs with consistent condom use in the last 30 days (aOR = 1.39, [95% CI: 1.05-1.82]), and FSWs experiencing at least one STI symptom in the last 12 months (aOR = 1.74 [95% CI: 1.34-2.26]). There was an inverse relationship between HIV prevalence and comprehensive HIV knowledge (aOR = 0.65, [95% CI: 0.48-0.88]). HIV prevalence was high among a sample of FSWs in Rwanda, and successful prevention strategies should focus on HIV education, treatment of sexually transmitted infections, and proper and consistent condom use using an outreach approach. |
Operating characteristics of a tuberculosis screening tool for people living with HIV in out-patient HIV care and treatment services, Rwanda
Turinawe K , Vandebriel G , Lowrance DW , Uwinkindi F , Mutwa P , Boer KR , Mutembayire G , Tugizimana D , Nsanzimana S , Pevzner E , Howard AA , Gasana M . PLoS One 2016 11 (9) e0163462 BACKGROUND: The World Health Organization (WHO) 2010 guidelines for intensified tuberculosis (TB) case finding (ICF) among people living with HIV (PLHIV) includes a recommendation that PLHIV receive routine TB screening. Since 2005, the Rwandan Ministry of Health has been using a five-question screening tool. Our study objective was to assess the operating characteristics of the tool designed to identify PLHIV with presumptive TB as measured against a composite reference standard, including bacteriologically confirmed TB. METHODS: In a cross-sectional study, the TB screening tool was routinely administered at enrolment in outpatient HIV care and treatment services at seven public health facilities. From March to September 2011, study enrollees were examined for TB disease irrespective of TB screening outcome. The examination consisted of a chest radiograph (CXR), three sputum smears (SS), sputum culture (SC) and polymerase chain reaction line-probe assay (Hain test). PLHIV were classified as having "laboratory-confirmed TB" with positive results on SS for acid-fast bacilli, SC on Lowenstein-Jensen medium, or a Hain test. RESULTS: Overall, 1,767 patients were enrolled and screened of which; 1,017 (57.6%) were female, median age was 33 (IQR, 27-41), and median CD4+ cell count was 385 (IQR, 229-563) cells/mm3. Of the patients screened, 138 (7.8%) were diagnosed with TB of which; 125 (90.5%) were laboratory-confirmed pulmonary TB. Of 404 (22.9%) patients who screened positive and 1,363 (77.1%) who screened negative, 79 (19.5%) and 59 (4.3%), respectively, were diagnosed with TB. For laboratory-confirmed TB, the tool had a sensitivity of 54.4% (95% CI 45.3-63.3), specificity of 79.5% (95% CI 77.5-81.5), PPV of 16.8% and NPV of 95.8%. CONCLUSION: TB prevalence among PLHIV newly enrolling into HIV care and treatment was 65 times greater than the overall population prevalence. However, the performance of the tool was poorer than the predicted performance of the WHO recommended TB screening questions. |
HIV surveillance in Rwanda: Readiness assessment to transition from antenatal care-based to prevention of mother to child transmission program-based HIV surveillance
Balisanga H , Mutagoma M , Remera E , Kayitesi C , Kayirangwa E , Dee J , Malamba S , Boer KR , Hedt-Gauthier B , Umugwaneza P , Nsanzimana S . Int J Infect Dis 2016 52 62-67 BACKGROUND: For efficiency and ethical considerations, in 2013 the World Health Organization (WHO) recommended to investigate transitioning from antenatal clinic-based surveillance to the prevention of mother to child transmission- (PMTCT-) based routine data. An assessment on the readiness for this transition was carried out in Rwanda in 2011 and 2013. METHODS: This assessment applied the WHO recommended methods which compares individual HIV rapid testing at site and antenatal surveillance results in all existing 30 sites involving 13,292 women. In addition, PMTCT HIV-testing quality assurance and PMTCT routine data quality were assessed in 27 out of 30 sites. RESULTS: All sentinel sites provided PMTCT services and had a high uptake of HIV testing (more than 90%). In all sites, PMTCT data were recorded in longitudinal and standardized ANC registers. Twenty six out of 27 sites had HIV result completeness above 90%. Positive percent agreement (97.5%) and negative percent agreement (99.9%) were observed between routine PMTCT and sero-surveillance HIV test results. Of 27 sites, 25 scored more than 80% in all phases of HIV testing quality assurance. CONCLUSIONS: According to WHO standards, Rwanda antenatal clinic HIV sero-surveillance is ready to transition to PMTCT-based sero-surveillance. |
A mixed outbreak of epidemic typhus fever and trench fever in a youth rehabilitation center: Risk factors for illness from a case-control study, Rwanda, 2012
Umulisa I , Omolo J , Muldoon KA , Condo J , Habiyaremye F , Uwimana JM , Muhimpundu MA , Galgalo T , Rwunganira S , Dahourou AG , Tongren E , Koama JB , McQuiston J , Raghunathan PL , Massung R , Gatei W , Boer K , Nyatanyi T , Mills EJ , Binagwaho A . Am J Trop Med Hyg 2016 95 (2) 452-6 In August 2012, laboratory tests confirmed a mixed outbreak of epidemic typhus fever and trench fever in a male youth rehabilitation center in western Rwanda. Seventy-six suspected cases and 118 controls were enrolled into an unmatched case-control study to identify risk factors for symptomatic illness during the outbreak. A suspected case was fever or history of fever, from April 2012, in a resident of the rehabilitation center. In total, 199 suspected cases from a population of 1,910 male youth (attack rate = 10.4%) with seven deaths (case fatality rate = 3.5%) were reported. After multivariate analysis, history of seeing lice in clothing (adjusted odds ratio [aOR] = 2.6, 95% confidence interval [CI] = 1.1-5.8), delayed (≥ 2 days) washing of clothing (aOR = 4.0, 95% CI = 1.6-9.6), and delayed (≥ 1 month) washing of beddings (aOR = 4.6, 95% CI = 2.0-11) were associated with illness, whereas having stayed in the rehabilitation camp for ≥ 6 months was protective (aOR = 0.20, 95% CI = 0.10-0.40). Stronger surveillance and improvements in hygiene could prevent future outbreaks. |
Discomfort glare comparison for various LED cap lamps
Sammarco JJ , Mayton AG , Lutz T , Gallagher S . IEEE Trans Ind Appl 2011 47 (3) 1168-1174 Researchers at the National Institute for Occupational Safety and Health (NIOSH) are investigating different lighting technologies with the objective of improving mine safety. This paper presents the results from an ongoing study that compares discomfort glare for different light-emitting diode (LED) cap lamps using the de Boer glare rating scale. The cap lamps tested included two commercially-available LED cap lamps and one NIOSH prototype LED cap lamp tested at three different illumination levels. Prior research indicated that the NIOSH prototype enabled much better visual performance as compared to other LED cap lamps. It uses three LEDs that produce multiple illumination areas in comparison to commercially-available cap lamps that use one LED and projects a narrow spot pattern. Across subjects and cap lamp test conditions, measured illuminances (averaged at both eyes) varied from 0.62 to 3.73 lx, whereas the de Boer glare ratings varied from 4.86 to 7.71. An analysis of variance based on 15 subjects indicated a significant difference in the discomfort glare due to cap lamps (F4, 52 = 18.01, p 0.001). Post hoc tests indicate that one of the commercially available cap lamps exhibited lower discomfort scores, with no statistically significant differences detected between the others. Thus, the NIOSH prototype cap lamp does not cause excessive discomfort glare yet enables better visual performance. 2011 IEEE. |
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