Article Text

The Peru Urban versus Rural Asthma (PURA) Study: methods and baseline quality control data from a cross-sectional investigation into the prevalence, severity, genetics, immunology and environmental factors affecting asthma in adolescence in Peru
  1. Colin L Robinson1,
  2. Lauren M Baumann1,
  3. Robert H Gilman2,3,4,
  4. Karina Romero3,
  5. Juan Manuel Combe3,
  6. Lilia Cabrera3,
  7. Nadia N Hansel1,5,
  8. Kathleen Barnes6,
  9. Guillermo Gonzalvez4,
  10. Robert A Wise1,5,
  11. Patrick N Breysse5,
  12. William Checkley1,2,3,4
  1. 1Division of Pulmonary and Critical Care, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
  2. 2Program in Global Disease Epidemiology and Control, Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
  3. 3A.B. PRISMA, Lima, Peru
  4. 4CRONICAS Center of Excellence for Chronic Diseases, Universidad Peruana Cayetano Heredia, Lima, Peru
  5. 5Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
  6. 6Division of Allergy and Clinical Immunology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
  1. Correspondence to Dr William Checkley; wcheckl1{at}jhmi.edu

Abstract

Objectives According to a large-scale international survey, Peru has one of the highest prevalences of asthma worldwide; however, data from this survey were limited to participants from urban Lima. The authors sought to characterise the epidemiology of asthma in Peru in two regions with disparate degrees of urbanisation. In this manuscript, the authors summarise the study design and implementation.

Design A cross-sectional study.

Participants Using census data of 13–15-year-old adolescents from two communities in Peru, the authors invited a random sample of participants in Lima (n=725) and all adolescents in Tumbes (n=716) to participate in our study.

Primary and secondary outcome measures The authors asked participants to complete a questionnaire on asthma symptoms, environmental exposures and socio-demographics and to undergo spirometry before and after bronchodilator, skin allergy testing and exhaled nitric oxide testing. The authors obtained blood samples for haematocrit, total IgE levels, vitamin D levels and DNA in all participants and measured indoor particulate matter concentrations for 48 h in a random subset of 70–100 households at each site.

Results Of 1851 eligible participants, 1441 (78%) were enrolled and 1159 (80% of enrolled) completed all physical tests. 1283 (89%) performed spirometry according to standard guidelines, of which 86% of prebronchodilator tests and 92% of postbronchodilator tests were acceptable and reproducible. 92% of allergy skin tests had an adequate negative control. The authors collected blood from 1146 participants (79%) and saliva samples from 148 participants (9%). Overall amounts of DNA obtained from blood or saliva were 25.8 μg, with a 260/280 ratio of 1.86.

Conclusions This study will contribute to the characterisation of a variety of risk factors for asthma, including urbanisation, total IgE levels, vitamin D levels and candidate genes, in a resource-poor setting. The authors present data to support high quality of survey, allergic, spirometric and genetic data collected in our study.

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited, the use is non commercial and is otherwise in compliance with the license. See: http://creativecommons.org/licenses/by-nc/2.0/ and http://creativecommons.org/licenses/by-nc/2.0/legalcode.

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Footnotes

  • To cite: Robinson CL, Baumann LM, Gilman RH, et al. The Peru Urban versus Rural Asthma (PURA) Study: methods and baseline quality control data from a cross-sectional investigation into the prevalence, severity, genetics, immunology and environmental factors affecting asthma in adolescence in Peru. BMJ Open 2012;2:e000421. doi:10.1136/bmjopen-2011-000421

  • Contributors All authors were involved in the study design and writing of the manuscript and reviewed the final manuscript before submission. CR directly contributed to the study design, supervision of field activities in Tumbes and Lima, is responsible for data management, data analysis and the writing of this manuscript. LB contributed equally to the study design, administration of fieldwork and data management and analysis. RG is the main investigator at the Lima site and provided technical support during the conduct of the study. KR, JMC and AG were the on-site study physicians who performed most physical testing and were extensively involved in administering fieldwork. LC is the fieldwork supervisor at the Lima site, provided census data and technical support. GG was the physician supervisor for research activities at the Tumbes site and provided census data and technical support. NH and RAW contributed to the study design and provided technical support for the study. KB contributed to the study design and provided logistical support for the study. PB contributed to study design of the environmental measurements and provided both technical support and equipment for our study. WC had ultimate oversight over study design and administration and was equally responsible for the analysis and writing of the manuscript. He also served as a mentor to CR and LB throughout the conduct of the study.

  • Funding Funding for the study was provided primarily by the Johns Hopkins Center for Global Health and the Fogarty International Center (Grant R24 TW007988). WC was further supported by a Clinician Scientist Award from the Johns Hopkins University and a K99/R00 Pathway to Independence Award (K99HL096955) from the National Heart, Lung and Blood Institute, National Institutes of Health and by a contract (HHSN268200900033C) with the National Heart, Lung and Blood Institute, National Institutes of Health. CR was a Fogarty International Clinical Research Scholar during the time of the study and was further supported by Tufts University School of Medicine. LB was supported by a NIH T35 Training Grant (T35AI065385). Additional support came from A.B. PRISMA and collaborators at JHU.

  • Competing interests None.

  • Patient consent Obtained.

  • Ethics approval Ethics approval was provided by JHU, PRISMA.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement No additional unpublished data are currently available for public use.

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