Showing papers by "Matthew P. Fox published in 2008"
TL;DR: Home treatment with high-dose oral amoxicillin is equivalent to currently recommended hospitalisation and parenteral ampicillin for treatment of severe pneumonia without underlying complications, suggesting that WHO recommendations for treatment for severe pneumonia need to be revised.
168 citations
TL;DR: Treatment had a large, positive impact on the ability of workers to undertake their primary work activity, harvesting tea, in the first year on ART, according to conservatively estimate that workers worked at least twice as many days in the month than they would have in the absence of ART.
Abstract: This paper estimates the impact of antiretroviral therapy (ART) on days harvesting tea per month for tea-estate workers in Kenya. Such information is needed to assess the potential economic benefits of providing treatment to working adults. Data for this analysis come from company payroll records for 59 HIV-infected workers and a comparison group of all workers assigned to the same work teams (reference group n = 1992) for a period covering 2 years before and 1 year after initiating ART. Mean difference tests were used to obtain overall trends in days harvesting tea by month. A difference in difference approach was used to estimate the impact of HIV/AIDS on days working in the pre-ART period. Information on likely trends in the absence of the therapy was used to estimate the positive impacts on days harvesting tea over the initial 12 months on ART. No significant difference existed in days plucking tea each month until the ninth month before initiating ART when workers worked -2.79 fewer days than references (15% less). This difference grew to 5.09 fewer days (27% less) in the final month before initiating ART. After 12 months on ART we conservatively estimate that workers worked at least twice as many days in the month than they would have in the absence of ART. Treatment had a large positive impact on the ability of workers to undertake their primary work activity harvesting tea in the first year on ART. (authors)
85 citations
TL;DR: Breast cancer survivors who are at greater risk of recurrence are less likely to receive surveillance mammograms, and women without a visit to an oncologist or breast cancer surgeon during a year have particularly low rates of mammography.
Abstract: Background
Annual surveillance mammography is recommended for follow-up of women with a history of breast cancer. We examined surveillance mammography among breast cancer survivors who were enrolled in integrated healthcare systems.
80 citations
TL;DR: The cost and cost-effectiveness of switching from d4T to tenofovir disoproxil fumarate (TDF) in South Africa is estimated and it would be highly cost effective at a price only slightly less than what is currently available.
Abstract: Background: Most first-line antiretroviral therapy regimens in Africa include stavudine (d4T), despite the high incidence of toxicities related to it. We estimated the cost and cost-effectiveness of switching from d4T to tenofovir disoproxil fumarate (TDF) in South Africa. Methods: A model was developed to estimate the proportion of patients in a hypothetical cohort who experienced d4T- and TDFrelated events over the 2 years after antiretroviral therapy initiation. Transition probabilities, event and drug costs, and utility losses were estimated from primary data and the literature. Outcomes included incremental cost, incremental cost-effectiveness ratio per qualityadjusted life year gained, and threshold prices for TDF. Results: After 2 years, 82.5% of the d4T scenario cohort remained on d4T, 16.6% had switched to AZT, 0.8% had died, and 414 events that did not lead to a drug change had occurred. In the TDF scenario, 97.5% of the cohort remained on TDF. At a baseline cost of TDF of $17.00/month, the incremental cost of the TDF scenario was $128/patient/year and the incremental cost-effectiveness ratio was $9007 per quality-adjusted life year gained. The change to TDF would be cost neutral for the government at a price of $6.17/month and highly cost effective at a price of $12.94/month. Conclusions: At a TDF price of $17.00/month, savings on d4T toxicity management will offset roughly 20% of the higher price of TDF. The price of TDF would have to fall substantially to make the change cost neutral for South Africa in budgetary terms, but it would be highly cost effective at a price only slightly less than what is currently available.
50 citations
TL;DR: Increased rates of colonization by pediatric serotypes suggest a potential role for the 7-valent pneumococcal vaccine in HIV-infected adults.
Abstract: Nasopharyngeal colonization with Streptococcus pneumoniae precedes invasive pneumococcal disease. Human immunodeficiency virus (HIV) infection increases rates of invasive pneumococcal disease, and its effect on colonization is unknown. In a longitudinal cohort of Zambian mothers with or without HIV infection, HIV infection increased the risk of colonization (risk ratio [RR], 1.9; 95% confidence interval [CI], 1.3-2.8) and repeat colonization (RR, 2.4; 95% CI, 1.1-5.3) and reduced the time to new colonization (P = .01). Repeat colonization with homologous sero/factor types occurred only among HIV-positive mothers. Pediatric serotypes 6, 19, and 23 accounted for excess colonization among HIV-positive mothers. HIV infection significantly increases the risk of pneumococcal colonization. Increased rates of colonization by pediatric serotypes suggest a potential role for the 7-valent pneumococcal vaccine in HIV-infected adults.
47 citations
TL;DR: Co-trimoxazole prophylaxis modestly suppresses pneumococcal colonization but accelerates infant acquisition of co-trimmingazole- and clindamycin-resistant pneumococci and appears unlikely to compromise the future efficacy of conjugate vaccines.
Abstract: OBJECTIVE: To ascertain the microbiological consequences of WHO's recommendation for presumptive co-trimoxazole prophylaxis for infants with perinatal HIV exposure. METHODS: Using a longitudinal cohort design, we followed HIV-exposed and HIV-unexposed infants trimonthly for up to 18 months per infant. HIV-exposed infants received daily co-trimoxazole prophylaxis from 6 weeks to > 12 months of age. Using Streptococcus pneumoniae as our sentinel pathogen, we measured how co-trimoxazole altered nasopharyngeal colonization, pneumococcal resistance to antibiotics and serotype distribution as a function of co-trimoxazole exposure. FINDINGS: From 260 infants followed for 3096 patient-months, we detected pneumococci in 360/1394 (25.8%) samples. HIV-exposed infants were colonized more frequently than HIV-unexposed infants (risk ratio, RR: 1.4; 95% confidence interval, CI: 1.0-1.9, P = 0.04). Co-trimoxazole prophylaxis reduced colonization by ca 7% but increased the risk of colonization with co-trimoxazole-resistant pneumococci within 6 weeks of starting prophylaxis (RR: 3.2; 95% CI: 1.3-7.8, P = 0.04). Prophylaxis with co-trimoxazole led to a small but statistically significant increase of nasopharyngeal colonization with pneumococci not susceptible to clindamycin (RR: 1.6; 95% CI: 1.0-2.6, P = 0.04) but did not increase the risk of non-susceptibility to penicillin (RR: 1.1; 95% CI: 0.7-1.7), erythromycin (RR: 1.0; 95% CI: 0.6-1.7), tetracycline (RR: 0.9; 95% CI: 0.6-1.5) or chloramphenicol (RR: 0.8; 95% CI: 0.3-2.3). Co-trimoxazole prophylaxis did not cause the prevailing pneumococcal serotypes to differ from those that are targeted by the 7-valent conjugate pneumococcal vaccine (RR: 1.0; 95% CI: 0.7-1.6). CONCLUSION: Co-trimoxazole prophylaxis modestly suppresses pneumococcal colonization but accelerates infant acquisition of co-trimoxazole- and clindamycin-resistant pneumococci. Co-trimoxazole prophylaxis appears unlikely to compromise the future efficacy of conjugate vaccines.
45 citations
TL;DR: This study demonstrates a survival benefit among children infected postpartum versus children infected during pregnancy or delivery and a benefit to increased breast-feeding duration among infected children.
Abstract: In developing countries where mother-to-child transmission of HIV through breast-feeding is common little is known about the impact of postpartum transmission on child survival. This study assessed whether children infected postpartum have longer survival from time of infection versus those infected during gestation or delivery. We used a prospective cohort study to analyze data from 213 HIV-infected children enrolled in a breast-feeding intervention trial in Lusaka Zambia (2001 to 2004). Methods: We compared mortality 1 year after HIV infection in children stratified by age of infection: 0 to 3 days (intrauterine (I/U) group) 4 to 40 days (intrapartum/early postpartum [IP/EPP] group) and greater than 40 days (postpartum [PP] group). A total of 61 71 and 81 children were infected in the I/U IP/EPP and PP groups respectively. Children with intrauterine or intrapartum/early postpartum transmission had higher mortality over the first 12 months after infection than children with postpartum transmission (P = 0.001 and P = 0.006 respectively); no differences were detected between children with intrauterine and intrapartum/ early postpartum transmission. Nearly 20% of the I/U and IP/EPP groups died by 100 days after infection whereas nearly 10% of the PP group had died by this time. After adjusting for birth weight maternal CD4 cell count breast-feeding and maternal death children infected postpartum had one quarter the mortality rate (hazard ratio [HR] = 0.27 95% confidence interval [CI]: 0.15 to 0.50) of those infected in utero. Stopping breast-feeding increased mortality in infected children (HR = 3.1 95% CI: 1.8 to 5.3). This study demonstrates a survival benefit among children infected postpartum versus children infected during pregnancy or delivery and a benefit to increased breast-feeding duration among infected children. Testing children for HIV early may provide a means to allow for earlier intervention. (authors)
18 citations
TL;DR: The discussion of the potential misclassification raises more questions than it answers, and readers want to know what is the expected magnitude and direction of the bias.
Abstract: In 2005, Ross and colleagues found a protective association between maternal multivitamin supplementation during the periconceptual period and acute lymphoblastic leukaemia among children with Down’s syndrome (OR 0.51; CI 0.30 to 0.89).1 In their discussion they noted, “Maternal vitamin supplementation was collected by self-report, which is subject to…recall bias. However, a validation study…reported excellent agreement...” The validation study appears to imply that the bias from misclassification should be minimal. But given the number of false-positive published research findings,2 which are partly explained by issues of misclassification, the discussion of the potential misclassification raises more questions than it answers.
First, we want to know what is the expected magnitude and direction of the bias. Second, given the potential bias, how we should interpret the 95% CI which is calculated assuming no bias?3 And how should we as readers integrate ideas about the magnitude and direction of the bias into our interpretation of the results. For example, if we believe the misclassification …
15 citations