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PubMed2007

A comparison of anion concentration in surficial groundwater sampled from two types of water quality monitoring wells.

Groundwater sampling for monitoring the presence and concentration of contaminants can be done using either depth integrated monitoring wells (MW) or depth specific multi-level sampling (MLS) wells. Depth specific multi-level sampling wells (MLS) are cost-effective, easy to install, and provide very detailed information about the vertical gradient in contaminant concentration. In contrast the MW sampling provides information on the presence of contaminant over large representative area. This study was conducted in two 33 ha blocks of a commercial citrus grove (Valencia orange trees on rough lemon rootstock) in a well drained Ashtabula fine sand (hyperthermic, uncoated, Typic Quartzipsamments). The depth to surficial groundwater at monitoring locations varied from 1.4 to 5.6 m, and the lateral groundwater flow rate was approximately 0.08 m d(-1). Anions were measured in groundwater sampled at 3-week intervals from four pair of MW and MLS in each of the two blocks. Since the screened portion of the MW in this study was placed in the top 150 cm of the surficial aquifer, the sampling parts of the MLS within this depth (2nd and 3rd ports) were considered for comparison. The results showed that the concentration of NO(-/3)-N, SO(2-/4) and Cl(-) in the MW samples were similar to the mean of the 2nd and 3rd port MLS sample concentrations over a one year period of sampling. Therefore, MLS sampling provides a technique to assess the groundwater quality very similar to that which can be obtainable by MW technique. In addition, the MLS provides useful information on the vertical gradient of solute concentrations thus allows evaluation of the short-term impacts of land management changes on solute concentrations in the very top layer of surficial aquifer in cost-effective manner.

Anions↗
PubMed1980

Beryllium sampling methods.

Three sampling methods for airborne beryllium are compared to validate observations made in a 1973 National Institute for Occupational Safety and Health (NIOSH) industrywide study of the beryllium industry which indicated that, in general, the three methods yielded different results for samples taken in the same environment. Under NIOSH contract a beryllium production facility was sampled in 1974 by the Atomic Energy Commission (AEC) personal total and personal respirable sampling methods over a period of one year. All samples were analyzed by atomic absorption spectroscopy. Statistical analysis of the resulting data by NIOSH confirms the observations made in the 1973 study that samples collected by the three methods produced different results. No reliable relationship was found to exist which would permit conversion of the result obtained by one method to a result obtained by either of the alternate methods. It appears that, in general, for large numbers of samples taken under the same sampling conditions, the values determined by the personal respirable sampling method will be lower than those obtained by the AEC method and the values determined by the personal total sampling method will be greater.

Air Pollutants↗
PubMed2006

An evaluation of analytical methods, air sampling techniques, and airborne occupational exposure of metalworking fluids.

This article summarizes an assessment of air sampling and analytical methods for both oil and water-based metalworking fluids (MWFs). Three hundred and seventy-four long-term area and personal airborne samples were collected at four plants using total (closed-face) aerosol samplers and thoracic samplers. A direct-reading device (DustTrak) was also used. The processes sampled include steel tube making, automotive component manufacturing, and small part manufacturing in a machine shop. The American Society for Testing and Materials (ASTM) Method PS42-97 of analysis was evaluated in the laboratory. This evaluation included sample recovery, determination of detection limits, and stability of samples during storage. Results of the laboratory validation showed (a) the sample recovery to be about 87%, (b) the detection limit to be 35 microg, and (c) sample stability during storage at room temperature to decline rapidly within a few days. To minimize sample loss, the samples should be stored in a freezer and analyzed within a week. The ASTM method should be the preferred method for assessing metalworking fluids (MWFs). The ratio of thoracic aerosol to total aerosol ranged from 0.6 to 0.7. A similar relationship was found between the thoracic extractable aerosol and total extractable aerosol. The DustTrak, with 10-microm sampling head, was useful in pinpointing the areas of potential exposure. MWF exposure at the four plants ranged from 0.04 to 3.84 mg/m3 with the geometric mean ranging between 0.22 to 0.59 mg/m3. Based on this data and the assumption of log normality, MWF exposures are expected to exceed the National Institute for Occupational Safety and Health recommended exposure limit of 0.5 mg/m3 as total mass and 0.4 mg/m3 as thoracic mass about 38% of the time. In addition to controlling airborne MWF exposure, full protection of workers would require the institution of programs for fluid management and dermal exposure prevention.

Aerosols↗
PubMed2002

Quantitative radioimmunoimaging for radioimmunotherapy treatment planning: effect of reduction in data sampling on dosimetric estimates.

Quantitative radioimmunoimaging (serial anterior/posterior imaging and blood sampling) is useful for radioimmunotherapy treatment planning, but can be quite time consuming. To predict whether accurate radiation absorbed dose estimates can be maintained with a reduction in data sampling, 12 patients undergoing indium-111/yttrium-90 anti-CD20 monoclonal therapy for whom absorbed doses were estimated based on eight data samples (acquired at 0, 2, 4, 24, 48, 72, 96, and 144 h, respectively), were retrospectively reanalyzed using only five samples (0, 4, 24, 72, and 144 h, respectively). Calculated residence times (in h) and absorbed doses (in cGy), for the whole body, kidneys, liver, lungs, spleen, and red marrow were compared with the original values based on the eight samples using Student's paired t-test. Linear regression and Bland-Altman analysis of the two data sample groups was also performed. The mean residence times in the five- and eight-data samples groups were essentially the same (17.7 +/- 26.6 h [range, 0.3-79.0 h] versus 17.6 +/- 26.6 h [range, 0.3-79.5 h]; p = 0.72), as were the mean absorbed doses (336 +/- 411 cGy [range, 38-2434 cGy] versus 325 +/- 381 cGy [range, 39-2246 cGy]; p = 0.24). Also, the linear regressions were excellent (residence time y = 1.00x + 0.09 h [r = 0.99]; absorbed dose y = 1.06x - 7.74 cGy [r = 0.98]). Additionally, Bland-Altman analysis revealed no significant sample bias in residence time (0.03 +/- 0.68 h, 0.9% +/- 10.0) or absorbed dose (11 +/- 76 cGy, 1.0% +/- 9.3). These results demonstrate that reduced data sampling in quantitative radioimmunoimaging can be achieved without significantly altering radiation absorbed dose estimates, but with a significant savings in imaging, blood sampling, and processing time.

Humans↗
PubMed2005

Detection of Campylobacter jejuni in dairy farm environmental samples using SYBR Green real-time polymerase chain reaction.

The aim of this study was to evaluate a SYBR Green based real-time PCR assay using well-characterized primers to detect Campylobacter jejuni in naturally contaminated dairy farm environmental samples. Specificity of the assay was determined with 62 C. jejuni strains and 120 non-C. jejuni strains. Peak melting temperature obtained with melting curves specific for C. jejuni was 77.5 degrees C. Standard curves were constructed using mean threshold cycle (C(T)) and various concentrations of C. jejuni ranging from 10(0) to 10(8) colony forming units (CFU)/mL, which resulted in a linear relationship between C(T) and log input DNA. Correlation coefficients of standard curves based on pure culture of C. jejuni in broth and spiked cells in lagoon water were R(2) = 0.995 (slope = 3.21) and R(2) = 0.988 (slope = 3.22), respectively, and sensitivity limits were <10 and >10(3) CFU/mL, respectively. After 24-h enrichment, total C. jejuni counts of all samples spiked with 10(0) CFU/mL reached >10(5) CFU/mL, and the detection limit was improved from >10(3) CFU/mL to <10 CFU/mL of inoculum in broth. Eighty-two dairy farm environmental samples, including fecal slurry, feed/silage, lagoon water, drinking water, bulk tank milk, farm soil, and bedding material, were analyzed. The real-time PCR assay detected C. jejuni in 25 (30.4%) of 82 samples, with 17 (68%) of these samples being culture positive for C. jejuni. All samples that were positive by standard culture methods were also positive by the real-time PCR method. Mean C( T ) values of 48-h enriched cultures for 17 PCR-positive/culture-positive samples and eight PCR-positive/culture-negative samples were 21.4 +/- 3.6, and 34.6 +/- 1.5 (p < 0.0001), respectively. C( T ) values for negative samples were >38.0. These results indicate that the SYBR Green real-time PCR assay provides a specific, reproducible, and simple method for detecting C. jejuni in dairy farm environmental samples.

Animals↗
PubMed2003

SamCluster: an integrated scheme for automatic discovery of sample classes using gene expression profile.

MOTIVATION: Feature (gene) selection can dramatically improve the accuracy of gene expression profile based sample class prediction. Many statistical methods for feature (gene) selection such as stepwise optimization and Monte Carlo simulation have been developed for tissue sample classification. In contrast to class prediction, few statistical and computational methods for feature selection have been applied to clustering algorithms for pattern discovery. RESULTS: An integrated scheme and corresponding program SamCluster for automatic discovery of sample classes based on gene expression profile is presented in this report. The scheme incorporates the feature selection algorithms based on the calculation of CV (coefficient of variation) and t-test into hierarchical clustering and proceeds as follows. At first, the genes with their CV greater than the pre-specified threshold are selected for cluster analysis, which results in two putative sample classes. Then, significantly differentially expressed genes in the two putative sample classes with p-values < or = 0.01, 0.05, or 0.1 from t-test are selected for further cluster analysis. The above processes were iterated until the two stable sample classes were found. Finally, the consensus sample classes are constructed from the putative classes that are derived from the different CV thresholds, and the best putative sample classes that have the minimum distance between the consensus classes and the putative classes are identified. To evaluate the performance of the feature selection for cluster analysis, the proposed scheme was applied to four expression datasets COLON, LEUKEMIA72, LEUKEMIA38, and OVARIAN. The results show that there are only 5, 1, 0, and 0 samples that have been misclassified, respectively. We conclude that the proposed scheme, SamCluster, is an efficient method for discovery of sample classes using gene expression profile. AVAILABILITY: The related program SamCluster is available upon request or from the web page http://www.sph.uth.tmc.edu:8052/hgc/Downloads.asp.

Algorithms↗
PubMed2001

Contamination of coagulation tests with heparin from blood gas samples.

We investigated the possibility that samples of blood could be contaminated by heparinized blood gas syringes, giving spurious results in coagulation tests. We collected coagulation test samples before (n=5) and after (n=13) blood gas sampling from a venous cannula in a volunteer. The results of activated partial thromboplastin time (APTT) tests were compared between control samples and samples taken before and after blood gas sampling. The median APTT after blood gas sampling was 71 s, significantly higher than before (median 34 s, P<0.05). We conclude that heparin from blood gas sampling syringes can contaminate coagulation tests. Heparinized samples for blood gas analysis should be obtained after coagulation test samples have been obtained.

Anticoagulants↗
PubMed2005

Rapid analysis of 2,4-D in soil samples by modified Soxhlet apparatus using HPLC with UV detection.

The 2,4-dichlorophenoxy acetic acid (2,4-D) is used as a systemic herbicide to control broadleaf weeds in wheat, corn, range land/pasture land, sorghum, and barley. In this study, a fast and efficient method is developed by selection of modified extraction apparatus and high-performance liquid chromatography (HPLC)-UV conditions for the determination of 2,4-D in soil samples. The method is applied to the study of soil samples collected from the agricultural field. The herbicide is extracted from soil samples by acetonitrile in a modified Soxhlet apparatus. The advantages of the apparatus are that it uses small volume of organic solvent, reduced time of extraction, and better recovery of the analyte. The extract is filtered using a very fine microfiber paper. The total extract is concentrated in a rotatory evaporator, dried under ultrahigh pure N2, and finally reconstituted in 1 mL of acetonitrile. HPLC-UV at 228 nm is used for analysis. The herbicide is identified and quantitated using the HPLC system. The method is validated by the analysis of spiked soil samples. Recoveries obtained varied from 85% to 100% for spiked soil samples. The limit of quantitation (LOQ) and the limit of detection (LOD) are 0.010 and 0.005 parts per million (ppm), respectively, for spiked soil samples. The LOQ and LOD are 0.006 and 0.003 ppm for unspiked soil samples. The measured concentrations of 2,4-D in spiked soil samples are between 0.010 and 0.020 ppm with an average of 0.016 +/- 0.003 ppm. For unspiked soil samples it is between 0.006 ppm and 0.012 ppm with an average of 0.009 +/- 0.002 ppm. The measured concentrations of 2,4-D in soil samples are generally low and do not exceed the regulatory agencies guidelines.

2,4-Dichlorophenoxyacetic Acid↗
PubMedDate not supplied

Rapid screening of fentanyl (China White) powder samples by solid-phase radioimmunoassay.

We report the use of a solid-phase radioimmunoassay (RIA) to rapidly screen powder samples for various illicit fentanyl analogs. A 10-mg sample is dissolved in water, serial dilutions are made over a range of 1:10 to 1:100,000, and then duplicate 50-microL aliquots are analyzed by RIA. This method was verified by analyzing 18 "China White" samples, first by RIA and then by gas chromatography/mass spectrometry (GC/MS) with the spectrometrist blind to the results of the RIA. Of the samples, 11 were positive by radioimmunoassay and all were confirmed by GC/MS and found to contain fentanyl, alpha-methylfentanyl, fluorofentanyl, cis- and trans-3-methylfentanyl, thienylfentanyl, or cis- and trans-3-methylthienylfentanyl. The seven samples that were negative by RIA contained a variety of substances typically found in street drug samples--caffeine, codeine, and heroin--but none of the fentanyls. Differences in fentanyl concentration between samples were quite large, up to 300-fold; however, the drug seems to be uniformly distributed within a single sample. Thus, accidental overdose is more likely to result from the large intersample variability in drug concentration rather than the "clumping" of fentanyl within a sample. This solid-phase RIA provides a simple, rapid, and reliable screening method for detecting fentanyl and its illicit analogs in powder samples.

Dose-Response Relationship, Drug↗
PubMed2001

Analysis of morphine and codeine in samples adulterated with Stealth.

Stealth is an adulterant used to avoid detection of drug abuse. The product does have an effect on the ability to detect several drugs of abuse, including the opiates morphine and codeine. It has previously been shown that low concentration (2500 ng/mL morphine) samples adulterated with Stealth tested negative by both Roche OnLine and Microgenics CEDIA immunoassays, but those spiked with higher concentrations (6000 ng/mL of codeine and morphine glucuronide) were positive. Initial results showed confirmation analysis was also sometimes negatively impacted by this adulterant. Urine samples were spiked with 6000 ng/mL of codeine and/or morphine glucuronide to assess the effect of Stealth. Each individual sample was split into separate aliquots. One aliquot of each was adulterated with Stealth following package directions. The samples were then tested by immunoassay and gas chromatography-mass spectrometry (GC-MS). The control and adulterated aliquots were positive by both immunoassays. Results of GC-MS analysis of the Stealth-adulterated aliquots following standard procedures using deuterated internal standards proved unsuccessful in several cases. In 4 of 12 cases (33%), neither the drugs nor internal standards were recovered despite repeated attempts. In one other sample, recovery was dramatically reduced, making accurate quantitation impossible, whereas the unadulterated aliquots of the same samples posed no problem with recovery. Addition of sodium disulfite to the aliquots prior to extraction allowed recovery of the drugs and internal standards from all samples. Analysis of the samples showed the concentration of morphine and codeine decreased in some by as much as 17 and 30%, respectively. In other cases, there was essentially no difference in the concentration seen before and after adulteration, with or without disulfite treatment. Unless the initial concentration of opiate is near the cutoff, samples containing opiates are likely to be immunoassay positive, it is important to consider this procedure as an option for samples that screen positive but the opiates and their respective internal standards are not recovered for GC-MS analysis.

Codeine↗
PubMed2004

Evaluation of sequential presence-absence sampling plans for the diamondback moth (Plutellidae: Lepidoptera) in cruciferous crops in Australia.

Two sets of sequential presence-absence sampling plans for decision-making in the management of diamondback moth, Plutella xylostella (L.), were developed and evaluated. One set of sampling plans targeted the classification of proportions of infested plants, and the other set of sampling plans targeted the classification of larval density. The action thresholds investigated were 0.15, 0.25, 0.35, and 0.45 proportion of plants infested with larvae, and 0.2, 0.4, 0.6, and 0.8 larvae per plant. They are representative of the action thresholds currently practiced by Australian crucifer growers. For each sampling plan, the population range within which a minimal correct decision rate of 95% can be expected at a maximal average sample size of 50 plants (OC95ASN50) was specified. The closeness of an OC95ASN50 range to the target action threshold is a measure of the expected performance of the sampling plan. A closer distance reflects better performance. The OC95ASN50 ranges of the proportion-classification sampling plans were within 33-53% of the target action thresholds. The width of these OC95ASN50 ranges represents 73-87% of the entire population range (0-1). For the classification of larval density, an empirical proportion-density model was first established using data from different states and different cruciferous crops. The OC95ASN50 ranges of the density-classification sampling plans were within 57-75% of the target action threshold. Simulated sampling of 20 independent data sets showed that for most data sets the correct classification rate was at least 98% and the matching average sample size was <50 plants.

Animals↗
PubMed2004

Beat sampling accuracy in estimating spruce spider mite (Acari: Tetranychidae) populations and injury on juniper.

The use of a standardized beat sampling method for estimating spruce spider mite, Oligonychus ununguis (Jacobi) (Acari: Tetranychidae), densities on a widely used evergreen ornamental plant species, Juniperus chinensis variety 'Sargentii' A. Henry (Cupressaceae), was examined. There was a significant positive relationship between total spruce spider mite densities and spider mite densities from beat sampling on juniper. The slope and intercept of the relationship may be used by pest managers to predict total spider mite densities on plants from beat sample counts. Beat sampling dramatically underestimates the total number of spider mites on a foliage sample. The relationships between spruce spider mite feeding injury and spider mite density estimates from beat sampling juniper foliage and total spider mite counts on foliage were also examined. There was a significant positive relationship between spruce spider mite density as estimated from beat sampling and injury to the plants. There was a similar positive relationship between the total number of spruce spider mites and injury to the plants, suggesting that a pest manager could use beat sampling counts to estimate plant injury and related thresholds. These findings have important implications to decision-making for spruce spider mite control, especially as it relates to threshold levels and determining rates of predator releases. Further assessment of the effectiveness of beat and other sampling methods across multiple spider mite- host plant associations needs to be examined to enable pest managers to select sampling plans that are feasible and reliable.

Animals↗
PubMed2001

Kidney morcellation in laparoscopic nephrectomy for tumor: recommendations for specimen sampling and pathologic tumor staging.

Laparoscopic nephrectomy is a novel approach for small renal tumors in selected patients; however, removal of the kidney through the small laparoscopic abdominal wall incision site requires the kidney to be morcellated into small fragments while still in situ. Morcellation presents two problems for the pathologist. First, guidelines for optimal sampling of morcellated fragments have not been described. Second, morcellation precludes complete pTNM tumor staging, in particular, tumor size, margins, and renal vein involvement. Based on our initial experience with 23 laparoscopic nephrectomies/nephroureterectomies (13 clinically suspected neoplasms, confirmed pathologically as renal cell carcinoma [RCC, n = 7], urothelial carcinoma of the renal pelvis [n = 3], angiomyolipoma [n = 1], and cystic nephroma [n = 1], and 10 clinically benign entities) and a conservative statistical model, we present a decision analysis model of various specimen sampling protocols that optimize cost, labor, or time to diagnosis (single vs sequential sampling). Using the tumor-to-kidney volume ratio (TKR), calculated from preoperative radiologic imaging and specimen gross weight, several specimen sampling algorithms were compared. For the average situation in which TKR is > or =0.15, the algorithm that most significantly optimizes cost and labor is one that initially samples 5% of the morcellated specimen. However, additional sampling may be required in one fourth of the cases. The optimal amount of sampled tissue may indeed be less than 5% because this assumes no suspicious tissue is grossly visible and in all our cases of RCC grossly visible tumor was identified. Additional nomograms for a spectrum of TKR, sampling success, and cost are presented to allow pathologists their own discretion in determining optimal sampling of the morcellated kidney. Tumor staging is severely limited by morcellation. Tumor size, renal capsule involvement, and renal vein involvement cannot be fully pathologically evaluated for RCC, whereas invasion cannot be definitively assessed for urothelial carcinoma of the renal pelvis. Knowledge of the radiologic features (lesion size, capsule, and vein involvement) is important in sampling and staging morcellated kidneys removed laparoscopically.

Algorithms↗
PubMed2003

Free water 3H concentrations in serum samples collected during 1969-1992 in Akita, Japan.

The measurements for human and environmental samples from the 1960's and 1970's are important to understand the long-term transfer of 3H from the environment to the human body. The authors have previously reported 3H concentrations in diet samples collected in Akita Prefecture during 1969-1988. Serum samples from persons living in Akita Prefecture during 1969-1992 were recently obtained. The samples were originally gathered for medical examinations and stored in freezers at -20 degrees C. Composite samples from 100 persons on average were made for analysis. The free water 3H (FWT) concentrations in those samples were determined and compared with 3H concentrations in diet samples and precipitation. The long-term variation pattern of the FWT concentrations in the serum samples was similar to patterns in the diet samples and precipitation, but the FWT concentrations in the serum samples were slightly higher than those in the latter two. A single compartment model calculation showed that the apparent mean residence time of serum FWT was 1.4 y using precipitation as an input to the compartment.

Adolescent↗
PubMed1994

Improving the accuracy of 99Tcm-mercaptoacetyltriglycine clearance by using two blood samples instead of one? Paediatric Task Group of the EANM.

From a database of 133 patients (98 children and 35 adults) who underwent multiple blood sampling for 99Tcm-mercaptoacetyltriglycine (MAG3) clearance, we determined simplified algorithms allowing the estimation of clearance. A one-compartment model with two blood samples was applied. The best choices for the adult population were the 12 and 90 min blood samples, giving a standard error of the estimate (S.E.E.) of less than 10 ml min-1 1.73 m-2; for the children, the 10 and 80 min blood samples gave a S.E.E. of 20 ml min-1 1.73 m-2; for both the adults and the children, the 10 and 70 min blood samples gave the best results with, however, a S.E.E. of 19 ml min-1 1.73 m-2. The use of such a combined algorithm will therefore result in a degradation of the results in adults, suggesting that a separate algorithm for each group is preferable. We compared the accuracy of the two blood sample method to the one blood sample method based on previously published algorithms for children and adults, respectively. The S.E.E. was significantly lower, in adults as well as in children, using the empirical two blood sample method. This two blood sample method seems potentially useful for routine practice in adult patients. The advantages of using such a method in children is balanced by the practical problems inherent in the need to take a second blood sample during the first 10 min, at a time when the plasma activity is rapidly decreasing.

Adult↗
PubMed1978

Evaluation of endomyocardial biopsy in the diagnosis of cardiac rejection. A study using bioptome samples of formalin-fixed tissue.

The reliability of endomyocardial bioptome samples in detecting cardiac rejection was assessed in 26 formalin-fixed previously transplanted hearts. Thirteen human donor hearts (mean postoperative survival 128 days) and 13 baboon donor hearts (mean survival 16.5 days) were studied. Twenty samples were taken under direct vision from the endomyocardium of each heart with an Olympus bioptome catheter. A total of 397 tissue samples was examined "blindly" histologically (177 human and 220 baboon). The bioptome samples were assigned a histological rejection score and then compared with the score accorded multiple tissue sections from the same heart. Sample scores agreed with tissue section scores as follows: humans 86% (samples showed more severe alterations in 5% and less severe in 9%) and baboons 57% (samples more severe in 40% and less severe in 3%). Only 2 false-negative samples were encountered among 285 tissue samples from hearts showing rejection. Changes of rejection were equally distributed between the left and right ventricles. Endomyocardial sampling proved an accurate means of detecting the presence of rejection. In the baboon hearts the endomyocardium tended to show more severe changes than the rest of the myocardium.

Animals↗
PubMed2004

Transepithelial sampling of the uterine ectocervix with a stiff-bristled, spiral-shaped brush.

OBJECTIVE: To measure the depth of sampling of the uterine ectocervix with the use of a stiff-bristled, spiral-shaped brush (SpiraBrush Cx; Trylon Corporation, Torrance, CA). MATERIALS AND METHODS: Eligible hysterectomy specimens were identified. The ectocervix was brushed with an inked SpiraBrush Cx in four quadrants with either light (gentle) or heavy (forceful) pressure. The depth of sampling was determined histologically. RESULTS: Four normal uteri were sampled a total of 15 times. The entire epithelium was removed to the epithelial-stromal junction in three specimens and in one sample only a few basal cells remained with light pressure. The depth of sampling ranged from 0.2 mm to 0.4 mm. Heavy pressure resulted in the entire removal of epithelium in six samples, with the depth of sampling ranging from 0.2 mm to 0.7 mm. The stroma was disrupted in one sample. Results were uninformative in five samples. CONCLUSIONS: Sampling of the uterine ectocervix with the SpiraBrush Cx seems to be transepithelial in most cases.

Journal Article↗
PubMed2007

Concordance of self-collected and clinician-collected swab samples for detecting human papillomavirus DNA in women 18 to 32 years of age.

OBJECTIVE: The objective of this study was to determine whether self- and clinician-collected samples are comparable for human papillomavirus (HPV) detection. STUDY DESIGN: Three hundred seventy-four women aged 23 to 32 (population 1) and 211 women aged 18 to 25 (population 2) contributed self-collected vaginal and clinician-collected cervical and vulvovaginal samples for HPV DNA testing. Eighty-six women mailed in self-collected samples. RESULTS: Agreement between self-collected vaginal and clinician-collected combined cervical/vulvovaginal samples was excellent (population 1:92.0%, kappa = 0.81; population 2: 96.4%, kappa = 0.88), but self-collected samples were more concordant with clinician-collected cervical samples in population 2 (kappa = 0.84) than population 1 (kappa = 0.65) (P = 0.01). Age-adjusted HPV prevalence was slightly lower in mailed-in (21.5%) than in-clinic self-collected samples (26.8%). CONCLUSIONS: The combined clinician-collected cervical/vulvovaginal sample is most sensitive for detecting all female genital tract HPV infections. HPV concordance between cervical and vaginal samples may be better for newer infections. Larger studies are needed to determine whether mailed-in self-samples are as effective as those collected in a clinical setting.

Adolescent↗