Try a new search

Format these results:

Searched for:

person:mathek01

Total Results:

16


Progression of Friedreich ataxia: quantitative characterization over 5 years

Patel, Maya; Isaacs, Charles J; Seyer, Lauren; Brigatti, Karlla; Gelbard, Sarah; Strawser, Cassandra; Foerster, Debbie; Shinnick, Julianna; Schadt, Kimberly; Yiu, Eppie M; Delatycki, Martin B; Perlman, Susan; Wilmot, George R; Zesiewicz, Theresa; Mathews, Katherine; Gomez, Christopher M; Yoon, Grace; Subramony, Sub H; Brocht, Alicia; Farmer, Jennifer; Lynch, David R
OBJECTIVE: Friedreich ataxia (FRDA) is a progressive neurodegenerative disorder of adults and children. This study analyzed neurological outcomes and changes to identify predictors of progression and generate power calculations for clinical trials. METHODS: Eight hundred and twelve subjects in a natural history study were evaluated annually across 12 sites using the Friedreich Ataxia Rating Scale (FARS), 9-Hole Peg Test, Timed 25-Foot Walk, visual acuity tests, self-reported surveys and disability scales. Cross-sectional outcomes were assessed from recent visits, and longitudinal changes were gaged over 5 years from baseline. RESULTS: Cross-sectional outcomes correlated with measures of disease severity. Age, genetic severity (guanine-adenine-adenine [GAA] repeat length), and testing site predicted performance. Serial progression was relatively linear using FARS and composite measures of performance, while individual performance outcomes were nonlinear over time. Age strongly predicted change from baseline until removing the effects of baseline FARS scores, when GAA becomes a more important factor. Progression is fastest in younger subjects and subjects with longer GAA repeats. Improved coefficients of variation show that progression results are more reproducible over longer assessment durations. INTERPRETATION: While age predicted progression speed in simple analyses and may provide an effective way to stratify cohorts, separating the effects of age and genetic severity is difficult. Controlling for baseline severity, GAA is the major determinant of progression rate in FRDA. Clinical trials will benefit from enrollment of younger subjects, and sample size requirements will shrink with longer assessment periods. These findings should prove useful in devising gene therapy trials in the near future.
PMCID:5018581
PMID: 27648458
ISSN: 2328-9503
CID: 2254632

Social Support, Sexual Violence, and Transactional Sex Among Female Transnational Migrants to South Africa

Giorgio, Margaret; Townsend, Loraine; Zembe, Yanga; Guttmacher, Sally; Kapadia, Farzana; Cheyip, Mireille; Mathews, Catherine
OBJECTIVES: To examine the relationship between sexual violence and transactional sex and assess the impact of social support on this relationship among female transnational migrants in Cape Town, South Africa. METHODS: In 2012 we administered a behavioral risk factor survey using respondent-driven sampling to transnational migrant women aged between 16 and 39 years, born outside South Africa, living in Cape Town, and speaking English, Shona, Swahili, Lingala, Kirundi, Kinyarwanda, French, or Somali. RESULTS: Controlling for study covariates, travel-phase sexual violence was positively associated with engagement in transactional sex (adjusted prevalence ratio [APR] = 1.38; 95% confidence interval [CI] = 1.07, 1.77), and social support was shown to be a protective factor (APR = 0.84; 95% CI = 0.75, 0.95). The interaction of experienced sexual violence during migration and social support score was APR = 0.85 (95% CI = 0.66, 1.10). In the stratified analysis, we found an increased risk of transactional sex among the low social support group (APR = 1.56; 95% CI = 1.22, 2.00). This relationship was not statistically significant among the moderate or high social support group (APR = 1.04; 95% CI = 0.58, 1.87). CONCLUSIONS: Programs designed to strengthen social support may reduce transactional sex among migrant women after they have settled in their receiving communities.
PMCID:4880241
PMID: 27077356
ISSN: 1541-0048
CID: 2612222

HIV prevalence and risk behaviours among foreign migrant women residing in Cape Town, South Africa

Townsend, Loraine; Giorgio, Maggie; Zembe, Yanga; Cheyip, Mireille; Mathews, Catherine
HIV prevalence and risk behaviour among foreign migrants in South Africa has not been explored. This paper describes the effectiveness of respondent-driven sampling (RDS) to recruit foreign migrant women residing in Cape Town, reports HIV prevalence, and describes key characteristics among them. We conducted a biological and behavioural surveillance survey using RDS. After written informed consent, participants completed an audio computer assisted self-interview and provided a dried blood sample for HIV analysis. HIV prevalence was estimated to be 7 % (CI 4.9-9.5) among 935 women. HIV sero-positivity was associated with older age (p = 0.001), country of origin (p < 0.000), being unmarried (p < 0.000), having lived in South Africa for 3-5 years (p = 0.023), sexual debut at >/=15 years (p = 0.047), and having used a condom at last sex with a main partner (p = 0.007). Few women reported early sexual debut, or multiple sexual partners. RDS was successful in recruiting foreign migrant women.
PMCID:5778353
PMID: 24781639
ISSN: 1573-3254
CID: 2612192

An institutional strategy to increase minority recruitment to therapeutic trials

Anwuri, Victoria V; Hall, Lannis E; Mathews, Katherine; Springer, Brian C; Tappenden, Jennifer R; Farria, Dione M; Jackson, Sherrill; Goodman, Melody S; Eberlein, Timothy J; Colditz, Graham A
PURPOSE: Participation in therapeutic clinical trials rarely reflects the race and ethnic composition of the patient population. To meet National Institutes of Health-mandated goals, strategies to increase participation are required. We present a framework for institutional enhancement of minority clinical trial accrual. METHODS: We implemented structural changes on four levels to induce and sustain minority accrual to clinical trials: (1) leadership support; (2) center-wide policy change; (3) infrastructural process control, data analysis, and reporting; and (4) follow-up with clinical investigators. A Protocol Review and Monitoring Committee reviews studies and monitors accrual, and the Program for the Elimination Cancer Disparities leads efforts for proportional accrual, supporting the system through data tracking, Web tools, and feedback to investigators. RESULTS: Following implementation in 2005, minority accrual to therapeutic trials increased from 12.0 % in 2005 to 14.0 % in 2010. The "rolling average" minority cancer incidence at the institution during this timeframe was 17.5 %. In addition to therapeutic trial accrual rates, we note significant increase in the number of minorities participating in all trials (therapeutic and nontherapeutic) from 2005 to 2010 (346-552, 60 % increase, p < 0.05) compared to a 52 % increase for Caucasians. CONCLUSIONS: Implementing a system to aid investigators in planning and establishing targets for accrual, while requiring this component as a part of annual protocol review and monitoring of accrual, offers a successful strategy that can be replicated in other cancer centers, an approach that may extend to other clinical and translational research centers.
PMCID:3773025
PMID: 23846282
ISSN: 1573-7225
CID: 2596922

Analysis of the visual system in Friedreich ataxia

Seyer, Lauren A; Galetta, Kristin; Wilson, James; Sakai, Reiko; Perlman, Susan; Mathews, Katherine; Wilmot, George R; Gomez, Christopher M; Ravina, Bernard; Zesiewicz, Theresa; Bushara, Khalaf O; Subramony, S H; Ashizawa, Tetsuo; Delatycki, Martin B; Brocht, Alicia; Balcer, Laura J; Lynch, David R
To use optical coherence tomography (OCT) and contrast letter acuity to characterize vision loss in Friedreich ataxia (FRDA). High- and low-contrast letter acuity and neurological measures were assessed in 507 patients with FRDA. In addition, OCT was performed on 63 FRDA patients to evaluate retinal nerve fiber layer (RNFL) and macular thickness. Both OCT and acuity measures were analyzed in relation to genetic severity, neurologic function, and other disease features. High- and low-contrast letter acuity was significantly predicted by age and GAA repeat length, and highly correlated with neurological outcomes. When tested by OCT, 52.7 % of eyes (n = 110) had RNFL thickness values below the fifth percentile for age-matched controls. RNFL thickness was significantly lowest for those with worse scores on the Friedreich ataxia rating scale (FARS), worse performance measure composite Z 2 scores, and lower scores for high- and low-contrast acuity. In linear regression analysis, GAA repeat length and age independently predicted RNFL thickness. In a subcohort of participants, 21 % of eyes from adult subjects (n = 29 eyes) had macular thickness values below the first percentile for age-matched controls, suggesting that macular abnormalities can also be present in FRDA. Low-contrast acuity and RNFL thickness capture visual and neurologic function in FRDA, and reflect genetic severity and disease progression independently. This suggests that such measures are useful markers of neurologic progression in FRDA.
PMID: 23775342
ISSN: 0340-5354
CID: 484312

The quality of HIV testing services for adolescents in Cape Town, South Africa: do adolescent-friendly services make a difference?

Mathews, Catherine; Guttmacher, Sally J; Flisher, Alan J; Mtshizana, Yolisa Y; Nelson, Tobey; McCarthy, Jean; Daries, Vanessa
We used adolescent simulated clients to evaluate whether HIV testing services in clinics participating in an adolescent-friendly initiative in Cape Town were superior to regular clinic services. We found improved accessibility to HIV testing, but no impact on adolescent's experience of negative attitudes from health workers and confidentiality breaches.
PMID: 19167669
ISSN: 1879-1972
CID: 1817182

Health related quality of life measures in Friedreich Ataxia

Epstein, Elizabeth; Farmer, Jennifer M; Tsou, Amy; Perlman, Susan; Subramony, S H; Gomez, Christopher M; Ashizawa, Tetsuo; Wilmot, George R; Mathews, Katherine; Wilson, Robert B; Balcer, Laura J; Lynch, David R
Evaluation of therapeutic agents for Friedreich Ataxia (FA) has been limited by a lack of adequate markers of disease progression. We assessed the capacity of health related quality of life (HRQOL) questionnaires to reflect disease status in FA. The SF-36 and several symptom-specific scales were administered to an FA cohort. Scores were compared with norms for the United States population, and to a disease-free control group of similar age and gender. FA patients had significantly lower SF-36 Physical Component Summary scores (PCS) and Physical Functioning Subscale (PFS) scores, and both PCS and PFS scores correlated significantly with disease duration and disability status. Mental Component Summary scores (MCS) did not differ between FA patients and controls. Among symptom-specific scales, scores for the Pain Effects, Bladder Control, and Modified Fatigue Impact scales were significantly worse among FA patients than controls, and generally correlated with markers of disease progression. Findings of this study are consistent with the phenotypic characteristics of FA, and suggest that HRQOL measures are potentially useful as clinical markers of disease status in FA.
PMID: 18571673
ISSN: 0022-510x
CID: 174674

Written parental consent in school-based HIV/AIDS prevention research

Mathews, Catherine; Guttmacher, Sally J; Flisher, Alan J; Mtshizana, Yolisa; Hani, Andiswa; Zwarenstein, Merrick
OBJECTIVES: We examined the process of obtaining "active," written parental consent for a school-based HIV/AIDS prevention project in a South African high school by investigating (1) parental consent form return rates, (2) parents' recall and knowledge of the research, and (3) the extent to which this consent procedure represented parents' wishes about their child's involvement in the research. METHODS: This cross-sectional descriptive study comprised interviews with parents of children in grades eight and nine in a poor, periurban settlement in Cape Town. RESULTS: Within 2 weeks, 94% of 258 parents responded to a letter requesting written consent and of those, 93% consented, but subsequent interviews showed that 65% remembered seeing the consent form. At the end of the interview, 99% consented to their child's participation. CONCLUSIONS: These findings challenge many of the assumptions underlying active written parental consent. However, they should not be used to deny adolescents at high risk of HIV infection the opportunity to participate in prevention trials. Rather, researchers together with the communities in which the research is undertaken need to decide on appropriate informed consent strategies.
PMCID:1449350
PMID: 15983279
ISSN: 0090-0036
CID: 1817202

AIDS prevention through peer education [Comment]

Flisher, Alan J; Mathews, Catherine; Guttmacher, Sally; Abdullah, Fareed; Myers, Jonathan E
PMID: 15889845
ISSN: 0256-9574
CID: 1817212

Partner notification

Mathews, Catherine; Coetzee, Nicol; Zwarenstein, Merrick; Guttmacher, Sally
PMID: 15652101
ISSN: 1462-3846
CID: 1817222