Which cut-off level of urine cotinine:creatinine ratio (CCR) should be used to determine passive smoking prevalence in children in community based studies?

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File: /var/www/html/application/helpers/my_audit_helper.php
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Function: file_get_contents

File: /var/www/html/application/helpers/my_audit_helper.php
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Function: simplexml_load_file_from_url

File: /var/www/html/application/helpers/my_audit_helper.php
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Function: getPubMedXML

File: /var/www/html/application/controllers/Detail.php
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Function: pubMedSearch_Global

File: /var/www/html/application/controllers/Detail.php
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Function: pubMedGetRelatedKeyword

File: /var/www/html/index.php
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Function: require_once

Which cut-off level of urine cotinine:creatinine ratio (CCR) should be used to determine passive smoking prevalence in children in community based studies? | LitMetric