Urine cotinine as an index of smoking status in smokers during 96-hr abstinence: Comparison between gas chromatography/mass spectrometry and immunoassay test strips
ABSTRACT Biomarkers such as carbon monoxide (CO) and cotinine (a nicotine metabolite) are used in tobacco cessation studies to assess smoking status. CO is easy to assess, is inexpensive, and provides immediate results. However, the short half-life of CO may limit its ability to identify smokers who have abstained for several hours. Quantitative methods (e.g., gas chromatography/mass spectrometry, or GC/MS) for measuring urine cotinine, which has a longer half-life, are valid and reliable, though costly and time consuming. Recently developed semiquantitative urine cotinine measurement techniques (i.e., urine immunoassay test strips, or ITS) address these disadvantages, though the value of ITS as a means of identifying abstaining smokers has not been evaluated. The present study examined ITS as a measure of smoking status in temporarily abstaining smokers. A total of 236 breath and urine samples were collected from smokers who participated in two separate studies involving three independent, 96-hr (i.e., Monday-Friday), Latin-square-ordered, abstinence or smoking conditions; a minimum 72-hr washout separated each condition. Each urine sample was analyzed with GC/MS and ITS. Under these study conditions, CO demonstrated moderate sensitivity (83.1%) and strong specificity (100%), whereas ITS assessment showed strong sensitivity (98.5%) and weak specificity (58.5%). In this study of short-term abstinence, ITS classified as nonabstinent nearly half of the samples collected from abstaining smokers. However, it classified nearly all nonabstinent smokers as currently smoking. Validation of ITS using GC/MS results from smokers undergoing more than 96 hr of abstinence may be valuable.
- SourceAvailable from: Aristidis M. Tsatsakis
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- "The expired air CO measurement will be performed according to detailed written guidelines, while the person who will perform the measure will have been trained beforehand. Even though expired CO is a convenient, low-cost measurement, that may provide immediate results for the evaluation of smoking status , its short half-life (3-6 hours) can lead to false negatives  as it is able to detect only smokers who have smoked within the past several hours and therefore cannot be considered the most reliable biochemical marker for confirming the validity of smoking cessation, but it could be used to motivate pregnant women to quit. . "
ABSTRACT: Maternal smoking is the most significant cause of preventable complications during pregnancy, with smoking cessation during pregnancy shown to increase birth weight and reduce preterm birth among pregnant women who quit smoking. Taking into account the fact that the number of women who smoke in Greece has increased steadily throughout the previous decade and that the prevalence of smoking among Greek females is one of the highest in the world, smoking cessation should be a top priority among Greek health care professionals. The Maternal Smoking Cessation during Pregnancy Study (M-SCOPE), is a Randomized Control Trial (RCT) that aims to test whether offering Greek pregnant smokers a high intensity intervention increases smoking cessation during the third trimester of pregnancy, when compared to a low intensity intervention. Prospective participants will be pregnant smokers of more than 5 cigarettes per week, recruited up to the second trimester of pregnancy. Urine samples for biomarker analysis of cotinine will be collected at three time points: at baseline, at around the 32nd week of gestation and at six months post partum. The control group/low intensity intervention will include: brief advice for 5 minutes and a short leaflet, while the experimental group/intensive intervention will include: 30 minutes of individualized cognitive-behavioural intervention provided by a trained health professional and a self-help manual especially tailored for smoking cessation during pregnancy, while counselling will be based on the ''5 As.'' After childbirth, the infants' birth weight, gestational age and any other health related complications during pregnancy will be recorded. A six months post-partum a follow up will be performed in order to re-assess the quitters smoking status. If offering pregnant smokers a high intensity intervention for smoking cessation increases the rate of smoking cessation in comparison to a usual care low intensity intervention in Greek pregnant smokers, such a scheme if beneficial could be implemented successfully within clinical practice in Greece. ClinicalTrials.gov Identifier NCT01210118.BMC Public Health 12/2011; 11(1):903. DOI:10.1186/1471-2458-11-903 · 2.32 Impact Factor
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- "Unfortunately, the researchers did not report how the GC results compared to NicAlert strip results. Other researchers have made comparisons between NicAlert and GC results (Acosta et al., 2004). However, to our knowledge, no one has reported how NicAlert would perform with pregnant smokers. "
ABSTRACT: Decreasing smoking during pregnancy is an important public health priority. An important step towards decreasing smoking during pregnancy is wider dissemination of evidence-based smoking cessation interventions. One such intervention is contingency management wherein mothers earn vouchers exchangeable for retail items contingent on biochemically verified smoking abstinence. Wider dissemination may be possible by using smoking verification methods that require minimal training and equipment. One possibility is to use a cotinine-sensitive dipstick (NicAlert) rather than a bench-top cotinine analyzer, which is expensive and requires relatively extensive technician expertise, or breath carbon monoxide analysis, which is relatively nonspecific. The present study was conducted to begin examining the utility of cotinine-sensitive dipsticks for this purpose. Fifty urine samples from pregnant women enrolled in a smoking cessation program were analyzed to compare three different methods for verifying smoking status: NicAlert strips, a bench-top enzyme multiplied immunoassay technique (EMIT) analyzer, and gas chromatography (GC), the current gold standard for determining cotinine levels in urine. Agreement between GC and NicAlert results were high (96%) and comparable to agreement between GC and EMIT results (94%). Semi-quantitative measurements using NicAlert were low with only 30% of samples in agreement between GC and specific ranges given on the strips. NicAlert strips appear to be a valid measure of determining smoking status among pregnant smokers although not of absolute cotinine concentration. With minimal training and equipment required, NicAlert strips provide a potentially practical method for using urine cotinine to verify smoking status in community treatment settings.Drug and alcohol dependence 06/2011; 119(1-2):130-3. DOI:10.1016/j.drugalcdep.2011.05.014 · 3.28 Impact Factor
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- "In smokers attempting abstinence, CO [cutoff < 8 parts per million (ppm)] had a sensitivity of 83.1% and a specificity of 100%, whereas urine NicAlert® had a sensitivity of 98.5% and a specificity of 58.5% compared to cotinine assayed by gas chromatography/mass spectrometry (GC/MS) (Acosta et al., 2004). These data suggest that CO and urine NicAlert® may be more effective together than either measure alone in verifying self-reported abstinence (Acosta et al., 2004). "
ABSTRACT: As a biomarker of smoking, semiquantitative analysis of cotinine (NicAlert) offers several advantages over breath carbon monoxide (CO) and quantitative analysis of cotinine. Recent studies have used urine NicAlert and breath CO in combination to verify abstinence. However, no studies have evaluated the performance of saliva NicAlert against or in combination with breath CO. Breath CO, saliva NicAlert, and smoking history were compared in an urban population of daily smokers (n = 24) and nonsmokers (n = 25). Saliva NicAlert predicted self-reported smoking with 100% sensitivity and 96% specificity. At a cutoff of > 5 ppm, breath CO had 100% sensitivity and 100% specificity in predicting self-reported smoking. Breath CO was positively correlated with saliva NicAlert and negatively correlated with minutes since last cigarette. Saliva NicAlert had high sensitivity and specificity in identifying daily smokers. Compared to saliva NicAlert, breath CO level was more indicative of recent smoking. Future treatment studies should evaluate the performance of saliva NicAlert as an alternative to the urine test.Human Psychopharmacology Clinical and Experimental 01/2010; 25(1):80-3. DOI:10.1002/hup.1078 · 1.85 Impact Factor