A capture–recapture approach for screening using two diagnostic tests with availability of disease status for the test positives only

The article considers screening human populations with two screening tests. If any of the two tests is positive, then full evaluation of the disease status is undertaken; however, if both diagnostic tests are negative, then disease status remains unknown. This procedure leads to a data constellation in which, for each disease status, the 2 × 2 table associated with the two diagnostic tests used in screening has exactly one empty, unknown cell. To estimate the unobserved cell counts, previous approaches assume independence of the two diagnostic tests and use specific models, including the special mixture model of Walter or unconstrained capture–recapture estimates. Often, as is also demonstrated in this article by means of a simple test, the independence of the two screening tests is not supported by the data. Two new estimators are suggested that allow associations of the screening test, although the form of association must be assumed to be homogeneous over disease status. These estimators are modifications of the simple capture–recapture estimator and easy to construct. The estimators are investigated for several screening studies with fully evaluated disease status in which the superior behavior of the new estimators compared to the previous conventional ones can be shown. Finally, the performance of the new estimators is compared with maximum likelihood estimators, which are more difficult to obtain in these models. The results indicate the loss of efficiency as minor.

A capture-recapture approach for screening using two diagnostic tests with availability of disease status for the test positives only

The article considers screening human populations with two screening tests. If any of the two tests is positive, then full evaluation of the disease status is undertaken; however, if both diagnostic tests are negative, then disease status remains unknown. This procedure leads to a data constellation in which, for each disease status, the 2 x 2 table associated with the two diagnostic tests used in screening has exactly one empty, unknown cell. To estimate the unobserved cell counts, previous approaches assume independence of the two diagnostic tests and use specific models, including the special mixture model of Walter or unconstrained capture-recapture estimates. Often, as is also demonstrated in this article by means of a simple test, the independence of the two screening tests is not supported by the data. Two new estimators are suggested that allow associations of the screening test, although the form of association must be assumed to be homogeneous over disease status. These estimators are modifications of the simple capture-recapture estimator and easy to construct. The estimators are investigated for several screening studies with fully evaluated disease status in which the superior behavior of the new estimators compared to the previous conventional ones can be shown. Finally, the performance of the new estimators is compared with maximum likelihood estimators, which are more difficult to obtain in these models. The results indicate the loss of efficiency as minor.

Screening for lupus anticoagulant: improving the performance of the lupus-sensitive PTT-LA

Introduction: The aim of the present work was to verify whether calculating a ratio between clotting times obtained with the sensitive PTT-LA and a less sensitive activated partial thromboplastin time (aPTT)-reagent may represent a valuable aPTT-based screening strategy for lupus anticoagulants (LA). Methods: For the pilot study, plasma samples from normal subjects (n = 15) and from patients with LA (n = 10), therapeutic anticoagulation with vitamin K-antagonists (VKA) (n = 15) or unfractionated heparin (n = 15), coagulation factors deficiency (n = 16), and inhibitory antibodies against factor VIII or IX (n = 11) were studied. For the evaluation study, 1553 consecutive plasma samples from nonanticoagulated patients investigated for LA between January 2005 and December 2007 at our institution were studied. Following screening strategies were employed: Pathromtin-SL (aPTT-SL), PTT-LA (aPTT-LA), ratio aPTT-LA/aPTT-SL (aPTT-ratio), and Russell's viper venom (RVV) based LA-Check. LA positive samples were identified by mixing studies and diluted RVV confirmation test (LA-Check/LA-Sure). Results: Pilot study: All screening strategies had a 100% sensitivity, and the aPTT-ratio reached the highest specificity (82%; 95%CI: 74-90%). Within the evaluation study, following sensitivities for LA screening were observed: aPTT-SL 59.0% (95%CI: 57-61%), aPTT-LA 82.1% (95%CI: 80-84%), aPTT-ratio 92.3% (95%CI: 91-94), and LA-Check 83.3% (95%CI: 82-85%). Conclusion: Calculating a ratio between the LA-sensitive PTT-LA and the less sensitive Pathromtin-SL improves the performance of the PTT-LA itself and represents a simple and sensitive aPTT-based integrated strategy for LA screening.

Follow-up care after a health fair screening in three Houston neighborhoods in 2008

Background. Each year thousands of people participate in mass health screenings for diabetes and hypertension, but little is known about whether or not those who receive higher than normal screening results obtain the recommended follow-up medical care, or what barriers they perceive to doing so. ^ Methods. Study participants were recruited from attendees at three health fairs in low-income neighborhoods in Houston, Texas Potential participants had higher than normal blood pressure (> 90/140 mgHg) or blood glucose readings (100 mm/dL fasting or 140 mm/dL random). Study participants were called at one, two, and three months and asked if they had obtained follow-up medical care; those who had not yet obtained follow-up care were asked to identify barriers. Using a modified Aday-Andersen model of health service access, the independent variables were individual and community characteristics and self-perceived need. The dependent variable was obtaining follow-up care, with barriers to care a secondary outcome. ^ Results. Eighty-two study participants completed the initial questionnaire and 59 participants completed the study protocol. Forty-eight participants (59% under an intent to treat analysis, 81% of those completing the study protocol) obtained follow-up care. Those who completed the initial questionnaire and who reported a regular source of care were significantly more likely to obtain follow-up care. For those who completed the study protocol the relationship between having a regular source of care and obtaining follow-up care approached but did not reach significance. For those who completed the initial questionnaire, self-described health status, when examined as a binary variable (good, very good, excellent, or poor, fair, not sure) was associated with obtaining follow-up care for those who rated their health as poor, fair, or not sure. While the group who completed the study protocol did not reach statistical significance, the same relationship between self-described health status of poor, fair, or not sure and obtaining follow-up care was present. The participants who completed the study protocol and described their blood pressure as OK or a little high were statistically more likely to get follow-up care than those who described it as high or very high. All those on oral medications for hypertension (12/12) and diabetes (4/4) who were told to obtain follow-up care did so; however, the small sample size allows this correlation to be of statistical significance only for those treating hypertension. ^ The variables significantly associated with obtaining follow-up care were having a regular source of care, self-described health status of poor, fair, or not sure, self-described blood pressure of OK or a little high, and taking medication for blood pressure. ^ At the follow-up telephone calls, 34 participants identified barriers to care; cost was a significant barrier reported by 16 participants, and 10 reported that they didn’t have time because they were working long hours after Hurricane Ike. ^ The study included the offer of access assistance: information about nearby safety-net providers, a visit to or information from the Health Information Center at their Neighborhood Center location, or information from Project Safety Net (a searchable web site for safety net providers). Access assistance was offered at the health fairs and then again at follow-up telephone calls to those who had not yet obtained follow-up care. Of the 48 participants who reported obtaining follow-up care, 26 said they had made use of the access assistance to do so. The use of access assistance was associated with being Hispanic, not having health insurance or a regular source of care, and speaking Spanish. It was also associated with being worried about blood glucose. ^ Conclusion. Access assistance, as a community enabling characteristic, may be useful in aiding low-income people in obtaining medical care. ^

Abuse and neglect of elderly and independence in instrumental and basic activities of daily living.

Introduction: One of the known risk factors for abuse and neglect of the elderly is the decrease in functional capacity, contributing to self care dependency of instrumental activities of daily living and basic activities of daily living (OMS, 2015). Methods: Cross-sectional study with non probabilistic sample of 333 elderly, performed in a hospital, homes and day centers for the elderly. The data collection protocol included socio-demographic data, Questions to elicit Elder Abuse (Carney, Kahan & Paris, 2003 adap. By Ferreira Alves & Sousa, 2005), scale of instrumental activities of daily living Lawton and Brody and Katz index to assess the level of independence in activities of daily living. Objectives: To evaluate the association between abuse and neglect in the elderly, instrumental activities of daily living and level of independence in activities of daily living. Results: Emotional abuse is significantly correlated with the level of independence in activities of daily living (p = 0.000), older people with less independence tend to have higher levels of emotional abuse. The total abuse is significantly correlated with the levels of independence in activities of daily living (p = 0.002), less independent elderly tend to suffer greater abuse and neglect. There were no statistically significant associations between abuse and neglect and instrumental activities of daily living. Conclusions: The less independent elderly are more vulnerable to situations of abuse and neglect, being more exposed to emotional abuse. These results point to the need for health professionals/ nurses develop prevention interventions, including strategies to support carers and early screening in less independent elderly.

Abuse and neglect of elderly and independence in instrumental and basic activities of daily living

Introduction: One of the known risk factors for abuse and neglect of the elderly is the decrease in functional capacity, contributing to self care dependency of instrumental activities of daily living and basic activities of daily living (OMS, 2015). Methods: Cross-sectional study with non probabilistic sample of 333 elderly, performed in a hospital, homes and day centers for the elderly. The data collection protocol included socio-demographic data, Questions to elicit Elder Abuse (Carney, Kahan & Paris, 2003 adap. By Ferreira Alves & Sousa, 2005), scale of instrumental activities of daily living Lawton and Brody and Katz index to assess the level of independence in activities of daily living. Objectives: To evaluate the association between abuse and neglect in the elderly, instrumental activities of daily living and level of independence in activities of daily living. Results: Emotional abuse is significantly correlated with the level of independence in activities of daily living (p = 0.000), older people with less independence tend to have higher levels of emotional abuse. The total abuse is significantly correlated with the levels of independence in activities of daily living (p = 0.002), less independent elderly tend to suffer greater abuse and neglect. There were no statistically significant associations between abuse and neglect and instrumental activities of daily living. Conclusions: The less independent elderly are more vulnerable to situations of abuse and neglect, being more exposed to emotional abuse. These results point to the need for health professionals/ nurses develop prevention interventions, including strategies to support carers and early screening in less independent elderly.

Newborn Hearing Screening And Early Diagnostic In The Nicu.

The aim was to describe the outcome of neonatal hearing screening (NHS) and audiological diagnosis in neonates in the NICU. The sample was divided into Group I: neonates who underwent NHS in one step and Group II: neonates who underwent a test and retest NHS. NHS procedure was automated auditory brainstem response. NHS was performed in 82.1% of surviving neonates. For GI, referral rate was 18.6% and false-positive was 62.2% (normal hearing in the diagnostic stage). In GII, with retest, referral rate dropped to 4.1% and false-positive to 12.5%. Sensorineural hearing loss was found in 13.2% of infants and conductive in 26.4% of cases. There was one case of auditory neuropathy spectrum (1.9%). Dropout rate in whole process was 21.7% for GI and 24.03% for GII. We concluded that it was not possible to perform universal NHS in the studied sample or, in many cases, to apply it within the first month of life. Retest reduced failure and false-positive rate and did not increase evasion, indicating that it is a recommendable step in NHS programs in the NICU. The incidence of hearing loss was 2.9%, considering sensorineural hearing loss (0.91%), conductive (1.83%) and auditory neuropathy spectrum (0.19%).

[why Does The Prevalence Of Cytopathological Results Of Cervical Cancer Screening Can Vary Significantly Between Two Regions Of Brazil?].

To analyze the prevalence of cervical cytopathological results for the screening of cervical cancer with regard to women's age and time since the last examination in Maceió and Rio de Janeiro, Brazil, among those assisted by the Brazilian Unified Health System. Cervical cytopathological results available in the Information System of Cervical Cancer Screening for the year 2011 were analyzed, corresponding to 206,550 for Rio de Janeiro and 45,243 for Maceió. In Rio de Janeiro, examination at one and two year intervals predominated, while in Maceió examination at one and three year intervals had a higher predominance. Women who underwent cervical smear screening in Maceió were older than those in Rio de Janeiro. The prevalence of invasive squamous cell carcinoma was similar for the two cities, but all the other results presented a higher prevalence in Rio de Janeiro: ASCUS (PR=5.32; 95%CI 4.66-6.07); ASCH (PR=4.27; 95%CI 3.15-5.78); atypical glandular cells (PR=10.02; 95%CI 5.66-17.76); low-grade squamous intraepithelial lesions (PR=6.10; 95%CI 5.27-7.07); high-grade squamous intraepithelial lesions (PR=8.90; 95%CI 6.50-12.18) and adenocarcinoma (PR=3.00; 95%CI 1.21-7.44). The rate of unsatisfactory cervical samples was two times higher in Maceió and that of rejected samples for analysis was five times higher in Maceió when compared to Rio de Janeiro. The prevalence rates of altered cervical cytopathological results was significantly higher in Rio de Janeiro than in Maceió. There is no objective information that may justify this difference. One hypothesis is that there may be a difference in the diagnostic performance of the cervical cancer screening, which could be related to the quality of the Pap smear. Thus, these findings suggest that it would be necessary to perform this evaluation at national level, with emphasis on the performance of cervical cancer screening in order to improve the effectiveness of cervical cancer control.

Relationship Between Lower-limb Muscle Strength And Functional Independence Among Elderly People According To Frailty Criteria: A Cross-sectional Study.

Muscle strength and functional independence are considered to be determinants of frailty levels among elderly people. The aim here was to compare lower-limb muscle strength (LLMS) with functional independence in relation to sex, age and number of frailty criteria, and to ascertain the influence of these variables on elderly outpatients' independence. Quantitative cross-sectional study, in a tertiary hospital. The study was conducted on 150 elderly outpatients of both sexes who were in a cognitive condition allowing oral communication, between October 2005 and October 2007. The following instruments were used: five-times sit-to-stand test (FTSST), Functional Independence Measurement (FIM) and Lawton's Instrumental Activities of Daily Living Scale (IADL). Descriptive, comparative, multivariate, univariate and Cronbach alpha analyses were performed. The mean time taken in the FTSST was 21.7 seconds; the mean score for FIM was 82.2 and for IADL was 21.2; 44.7% of the subjects presented 1-2 frailty criteria and 55.3% > 3 criteria. There was a significant association between LLMS and functional independence in relation to the number of frailty criteria, without homogeneity regarding sex and age. Functional independence showed significant influence from sex and LLMS. Elderly individuals with 1 or 2 frailty criteria presented greater independence in all FTSST scores. The subjects with higher LLMS presented better functional independence.

Microbial Lipid Production: Screening With Yeasts Grown On Brazilian Molasses.

Rhodotorula glutinis CCT 2182, Rhodosporidium toruloides CCT 0783, Rhodotorula minuta CCT 1751 and Lipomyces starkeyi DSM 70296 were evaluated for the conversion of sugars from Brazilian molasses into single-cell oil (SCO) feedstock for biodiesel. Pulsed fed-batch fermentations were performed in 1.65 l working volume bioreactors. The maximum specific growth rate (µmax), lipid productivity (Pr) and cellular lipid content were, respectively, 0.23 h(-1), 0.41 g l(-1) h(-1), and 41% for Rsp. toruloides; 0.20 h(-1), 0.27 g l(-1) h(-1), and 36% for Rta. glutinis; 0.115 h(-1), 0.135 g l(-1) h(-1), and 27 % for Rta. minuta; and 0.11 h(-1), 0.13 g l(-1) h(-1), and 32% for L. starkeyi. Based on their microbial lipid productivity, content, and profile, Rsp. toruloides and Rta. glutinis are promising candidates for biodiesel production from Brazilian molasses. All the oils from the yeasts were similar to the composition of plant oils (rapeseed and soybean) and could be used as raw material for biofuels, as well as in food and nutraceutical products.

Screening The Life Cycle Of Schistosoma Mansoni Using High-resolution Mass Spectrometry.

Schistosomiasis is a common tropical disease caused by Schistosoma species Schistosomiasis' pathogenesis is known to vary according to the worms' strain. Moreover, high parasitical virulence is directly related to eggs release and granulomatous inflammation in the host's organs. This virulence might be influenced by different classes of molecules, such as lipids. Therefore, better understanding of the metabolic profile of these organisms is necessary, especially for an increased potential of unraveling strain virulence mechanisms and resistance to existing treatments. In this report, direct-infusion electrospray high-resolution mass spectrometry (ESI(+)-HRMS) along with the lipidomic platform were employed to rapidly characterize and differentiate two Brazilian S. mansoni strains (BH and SE) in three stages of their life cycle: eggs, miracidia and cercariae, with samples from experimental animals (Swiss/SPF mice). Furthermore, urine samples of the infected and uninfected mice were analyzed to assess the possibility of direct diagnosis. All samples were differentiated using multivariate data analysis, PCA, which helped electing markers from distinct lipid classes; phospholipids, diacylglycerols and triacylglycerols, for example, clearly presented different intensities in some stages and strains, as well as in urine samples. This indicates that biochemical characterization of S. mansoni may help narrowing-down the investigation of new therapeutic targets according to strain composition and aggressiveness of disease. Interestingly, lipid profile of infected mice urine varies when compared to control samples, indicating that direct diagnosis of schistosomiasis from urine may be feasible.

[factors Impacting The Growth And Nutritional Status Of Cystic Fibrosis Patients Younger Than 10 Years Of Age Who Did Not Undergo Neonatal Screening.]

The aim of this study was to evaluate by clinical and laboratory parameters how cystic fibrosis (CF) affects growth and nutritional status of children who were undergoing CF treatment but did not receive newborn screening. A historical cohort study of 52 CF patients younger than 10 years of age were followed in a reference center in Campinas, Southeast Brazil. Anthropometric measurements were abstracted from medical records until March/2010, when neonatal screening program was implemented. Between September/2009 and March/2010, parental height of the 52 CF patients were also measured. Regarding nutritional status, four patients had Z-scores ≤ -2 for height/age (H/A) and body mass index/age (BMI/A). The following variables were associated with improved H/A ratio: fewer hospitalizations, longer time from first appointment to diagnosis, longer time from birth to diagnosis and later onset of respiratory disease. Forced vital capacity [FVC(%)], forced expiratory flow between 25-75% of FVC [FEF25-75(%)], forced expiratory volume in the first second [FEV1(%)], gestational age, birth weight and early respiratory symptoms were associated with IMC/A. Greater number of hospitalizations, diagnosis delay and early onset of respiratory disease had a negative impact on growth. Lower spirometric values, lower gestational age, lower birth weight, and early onset of respiratory symptoms had negative impact on nutritional status. Malnutrition was observed in 7.7% of cases, but 23% of children had nutritional risk.

In Vivo Evaluation Of The Genetic Toxicity Of Rubus Niveus Thunb. (rosaceae) Extract And Initial Screening Of Its Potential Chemoprevention Against Doxorubicin-induced Dna Damage.

Rubus niveus Thunb. plant belongs to Rosaceae family and have been used traditionally to treat wounds, burns, inflammation, dysentery, diarrhea and for curing excessive bleeding during menstrual cycle. The present study was undertaken to investigate the in vivo genotoxicity of Rubus niveus aerial parts extract and its possible chemoprotection on doxorubicin (DXR)-induced DNA damage. In parallel, the main phytochemicals constituents in the extract were determined. The animals were exposed to the extract for 24 and 48h, and the doses selected were 500, 1000 and 2000mg/kg b.w. administered by gavage alone or prior to DXR (30mg/kg b.w.) administered by intraperitoneal injection. The endpoints analyzed were DNA damage in bone marrow and peripheral blood cells assessed by the alkaline alkaline (pH>13) comet assay and bone marrow micronucleus test. The results of chemical analysis of the extract showed the presence of tormentic acid, stigmasterol, quercitinglucoronide (miquelianin) and niga-ichigoside F1 as main compounds. Both cytogenetic endpoints analyzed showed that there were no statistically significant differences (p>0.05) between the negative control and the treated groups with the two higher doses of Rubus niveus extract alone, demonstrating absence of genotoxic and mutagenic effects. Aneugenic/clastogenic effect was observed only at 2000mg/kg dose. On the other hand, in the both assays and all tested doses were observed a significant reduction of DNA damage and chromosomal aberrations in all groups co-treated with DXR and extract compared to those which received only DXR. These results indicate that Rubus niveus aerial parts extract did not revealed any genotoxic effect, but presented some aneugenic/clastogenic effect at higher dose; and suggest that it could be a potential adjuvant against development of second malignant neoplasms caused by the cancer chemotherapic DXR.

In Vitro Biological Screening Of The Anticholinesterase And Antiproliferative Activities Of Medicinal Plants Belonging To Annonaceae.

The aim of this research was to investigate the antiproliferative and anticholinesterase activities of 11 extracts from 5 Annonaceae species in vitro. Antiproliferative activity was assessed using 10 human cancer cell lines. Thin-layer chromatography and a microplate assay were used to screen the extracts for acetylcholinesterase (AchE) inhibitors using Ellman's reagent. The chemical compositions of the active extracts were investigated using high performance liquid chromatography. Eleven extracts obtained from five Annonaceae plant species were active and were particularly effective against the UA251, NCI-470 lung, HT-29, NCI/ADR, and K-562 cell lines with growth inhibition (GI50) values of 0.04-0.06, 0.02-0.50, 0.01-0.12, 0.10-0.27, and 0.02-0.04 µg/mL, respectively. In addition, the Annona crassiflora and A. coriacea seed extracts were the most active among the tested extracts and the most effective against the tumor cell lines, with GI50 values below 8.90 µg/mL. The A. cacans extract displayed the lowest activity. Based on the microplate assay, the percent AchE inhibition of the extracts ranged from 12 to 52%, and the A. coriacea seed extract resulted in the greatest inhibition (52%). Caffeic acid, sinapic acid, and rutin were present at higher concentrations in the A. crassiflora seed samples. The A. coriacea seeds contained ferulic and sinapic acid. Overall, the results indicated that A. crassiflora and A. coriacea extracts have antiproliferative and anticholinesterase properties, which opens up new possibilities for alternative pharmacotherapy drugs.