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PubMed1993

Early hospital discharge and the timing of newborn metabolic screening.

Cost containment measures have reduced dramatically the length of stay for normal newborns, in some cases jeopardizing the ability to obtain appropriate newborn screens. In our hospital, we found that an unacceptable number of patients had mistakenly been screened before 24 hours of age. As pressures to shorten hospitalization increase, health-care providers must examine the impact of such changes on their ability to obtain adequate newborn screens. Potential solutions include continued vigilance in gathering specimens after 24 hours of age, interpretation of time-sensitive tests in an age-adjusted manner, and repeating newborn screens after 24 hours of age.

Cesarean Section↗
PubMed1985

Screening for gestational diabetes. Optimum timing and criteria for retesting.

Because of the morbidity associated with undiagnosed gestational diabetes (GDM), screening programs are advocated in all pregnancy clinics. The purpose of this study was to elucidate the optimum time to test for diabetes during gestation, the indication for retesting, and the predictive value of a positive screening test for a large (greater than 4000 g) infant. Women (N = 300) were screened at three time points: 9-20 wk, 27-31 wk, and 33-36 wk. An additional group of 300 women were screened at two time points: 27-31 wk and 33-36 wk. The prevalence of GDM in this group was 3.2%. The optimum timing for screening for highest yield was 27-31 wk. Retesting at 33-36 wk appeared cost effective if (1) maternal age was greater than or equal to 33 yr, (2) a positive screen was present at 27-31 wk, and (3) the mother was obese (greater than 120% ideal body wt).

Adult↗
PubMed1995

Estimation of mean sojourn time in breast cancer screening using a Markov chain model of both entry to and exit from the preclinical detectable phase.

The sojourn time, time spent in the preclinical detectable phase (PCDP) for chronic diseases, for example, breast cancer, plays an important role in the design and assessment of screening programmes. Traditional methods to estimate it usually assume a uniform incidence rate of preclinical disease from a randomized control group or historical data. In this paper, a two-parameter Markov chain model is proposed and developed to explicitly estimate the preclinical incidence rate (lambda 1) and the rate of transition from preclinical to clinical state (lambda 2, equivalent to the inverse of mean sojourn time) without using control data. A new estimate of sensitivity is proposed, based on the estimated parameters of the Markov process. When this method is applied to the data from the Swedish two-county study of breast cancer screening in the age group 70-74, the estimate of MST is 2.3 with 95 per cent CI ranging from 2.1 to 2.5, which is close to the result based on the traditional method but the 95 per cent CI is narrower using the Markov model. The reason for the greater precision of the latter is the fuller use of all temporal data, since the continuous exact times to events are used in our method instead of grouping them as in the traditional method. Ongoing and future researches should extend this model to include, for example, the tumour size, nodal status and malignancy grade, along with methods of simultaneously estimating sensitivity and the transition rates in the Markov process.

Adult↗
PubMed2002

Commercial variants of the prothrombin time test as a screening test of acquired coagulation factor II, VII, and X deficiencies in dogs.

The aim of this study was to acquire the single factor sensitivity of three commercial variants of the prothrombin time test (PT(Va1)-Thrombotest, PT(Va2)-Normotest, PT(Va3)-Hepato Quick) for canine plasma. For this purpose, 38 samples from animals with coumarin intoxication followed by vitamin K(1) treatment who had a reduced activity of the coagulation factors II, VII, and/or X (experiment 1) as well as 25 plasma samples from animals with moderately reduced activity of the coagulation factors II, V, VII, and/or X caused by a hepatogenic synthesis disorder or disseminated intravascular coagulation (experiment 2), were examined. Measurements for all tests were performed according to the instructions of the manufacturer and also with higher plasma dilution. Furthermore, control measurements were performed with the conventional prothrombin time test (standard test; PT(ST)). The prothrombin time measured with the PT(Va3), which was prolonged in all samples from experiments 1 and 2, especially reflected with high sensitivity the reduced activity of the coagulation factors. The measurements with PT(Va2) and PT(Va1) showed only an insignificantly lower sensitivity (> or =0.88) with a maximum of 1 (experiment 1) and 3 (experiment 2) false negative test results, respectively. Compared to the already high sensitivity, a higher dilution of the sample material did not lead to a significantly higher sensitivity (P>0.05) for any of the tested commercial variants of the prothrombin time assay. While there was no significant difference (P>0.05) between the number of false negative test results in the variants of the prothrombin time assay, in both experiments a significantly higher number of false negative test results was found for the PT(ST) (P<0.001). The results show that, in contrast to the PT(ST), all three tested commercial prothrombin time variants are suitable for the detection of deficiencies of coagulation factors II, VII, and X in canine plasma.

Animals↗
PubMed2006

Applications of real-time PCR in the screening of platelet concentrates for bacterial contamination.

Although there have been major improvements over the past few decades in detection methods for blood-borne infectious agents, platelet concentrates are still responsible for most cases of transfusion-transmitted bacterial infections. To date, real-time PCR is an indispensable tool in diagnostic laboratories to detect pathogens in a variety of biological samples. In this article, the applications of this powerful technique in the screening of platelet concentrates for bacterial contamination are discussed. Next to pathogen-specific (real-time) PCR assays, particular attention is directed to the recently developed 16S rDNA real-time PCR. This assay has been proven as a convenient way to detect bacterial contamination of platelet concentrates. The assay is sensitive and enables rapid detection of low initial numbers of bacteria in platelet concentrates. The short turnaround time of this assay allows high-throughput screening and reduction of the risk of transfusion of bacterially contaminated units. As with every method, real-time PCR has its advantages and disadvantages. These and especially limitations inherent to generation of false-positive or -negative results are emphasized. The universal nature of detection of the assay may be suitable for generalized bacterial screening of other blood components, such as red blood cells and plasma. Therefore, it is necessary to adapt and optimize detection in red blood cells and plasma with real-time PCR. Further sophistication, miniaturization and standardization of extraction and amplification methods should improve the total performance and robustness of the assay. Hence, real-time PCR is an attractive method in development as a more rapid screening test than currently used culture methods to detect bacterial contamination in blood components.

Animals↗
PubMed1984

Ultrasonic screening in predicting the time of ovulation.

A consistent sign of imminent ovulation in the graafian follicle has been observed by ultrasonic screening. The sign is the appearance of a double contour along the follicle wall, with the wall losing its clear appearance. This is an important sign which can be used in all programs in which the exact timing of ovulation is important, in order to receive the best possible results in treatment of infertility.

Female↗
PubMed1978

A rapid screening test for reduced fibrinolytic activity of plasma: streptokinase activated lysis time.

A simple screening method for determining the fibrinolytic activity of plasma is described. A streptokinase activated system is used, which measures the result of the interplay of all components of the fibrinolytic system with the exception of activators, which are added in excess. Mean lysis time and standard deviation with this method is 6.9 +/- 1.4 min. The sensitivity of the method in detecting minor delays in clot lysis time is demonstrated.

Blood Coagulation Tests↗
PubMed2001

Breast screening attendance: making better use of an appointment system.

OBJECTIVES: To improve the effective use of screening appointment time on mobile units and even out the daily workload. SETTING: Ten sites screened by three Breast Test Wales mobile units between January and August 1999. METHODS: Women who had never attended for screening in previous screening rounds were identified and block booked into dedicated sessions at a rate of up to eight women per five minute slot. After piloting in the first site, the number in each slot was varied depending on how many rounds of screening these women had failed to attend. The numbers of women attending the remaining days were compared before and after the introduction of the new booking system. RESULTS: There was a noticeable difference in uptake rates for previous non-attenders depending on how many screening rounds they had missed. The uptake rate for women who had missed one round of screening was found to average 20%. For those who had missed two previous rounds it averaged 9% and for those who had missed three it averaged 3%. Before the change in booking procedure, the average attending each day was 51 (median 51), but after the change, the average was 57 (median 59). The overall time needed was decreased. CONCLUSIONS: Booking dedicated sessions for previous non-attenders results is a more effective use of resources, reducing screening time in every site and levelling out attendance.

Appointments and Schedules↗
PubMed2006

Incidentally discovered thyroid nodules: incidence, and greyscale and colour Doppler pattern in an adult population screened by real-time compound spatial sonography.

PURPOSE: Our aim was to assess the incidence and ultrasound features of thyroid nodules in an adult population screened by means of high-resolution ultrasonography (HRUS) and to evaluate the contribution of real-time spatial compound sonography (CS) in terms of image quality. MATERIALS AND METHODS: A total of 704 consecutive patients (400 women, 304 men) without thyroid disease underwent HRUS and CS examination of the thyroid gland. Number, size, location, echotexture and colour Doppler pattern of detected nodules were assessed. Two radiologists also assessed image quality of the two techniques. RESULTS: Seven hundred and eleven thyroid nodules (size range 0.18-4.1 cm; mean: 1.1 cm) were detected in 233 subjects (33.1%). Of these, 416 (58.5%) were found in 143 women whereas 295 (41.5%) were detected in 90 men. In both genders, the number of detected nodules increased with age, with the highest prevalence in the seventh decade (p<0.001). There were 461/711 (64.9%) thyroid nodules that were hypoechoic, and 449/711 (63.1%) had peripheral vascularity only (p<0.001). Fine-needle aspiration (FNA) revealed no malignancies. CS was graded better than HRUS in 621/711 (87.3%) cases (p<0.001). CONCLUSIONS: The prevalence of benign, small, hypoechoic thyroid nodules with peripheral vascularity was high in our series, thus suggesting a conservative approach. CS provided better image quality compared with HRUS.

Adolescent↗
PubMed2005

Analyses of neurobehavioral screening data: dose-time-response modeling of continuous outcomes.

Neurotoxic effects are a non-cancer endpoint for health risk, and neurobehavioral screening tests can serve as a first tier investigation of neurotoxicity [US EPA, Federal Register 63 (1998) 26926]. Analysis of neurobehavioral screening data such as those of the functional observational battery (FOB) traditionally relies on analysis of variance (ANOVA). ANOVA is designed to detect whether there are dose-effects, but does not model the underlying dose-response relationship and subsequent risk assessment fails to utilize the shape of the underlying dose-response. In contrast, dose-response modeling interpolates toxic effects between experimental points, and permits prediction of toxic effects within the experimental range. Additionally it is also a prerequisite for estimating a benchmark dose. This paper discusses dose-time-response modeling of longitudinal neurotoxicity data and illustrates the methods using three continuous FOB outcomes from an EPA study involving acute exposure to triethyltin (TET). Several mathematical functions are presented as candidate dose-time-response models. The use of random effects is discussed to characterize inter-subject variation. The results indicate that it is feasible to use simple mathematical functions to model empirical dose-time-response observed in existing longitudinal neurotoxicological data. Further research is needed on the types of design and data required to reliably approximate the true underlying dose-time-response.

Behavior↗
PubMed2005

Real-time RT-PCR for norovirus screening in shellfish.

Real-time RT-PCR, combining amplification and detection of virus-specific amplicons, is a promising tool for norovirus detection in environmental or food samples such as shellfish. We developed a real-time RT-PCR assay based on one-step detection using single primer sets and probes for norovirus genogroups I and II. Seventy and seven RT-PCR units of genogroup I and II reference norovirus strains, respectively, were detected in artificially contaminated oysters. Validation of the new method on 150 archived naturally contaminated shellfish confirmed the utility of the genogroup II primer set to detect a large range of different strains circulating in France since 1995, but genogroup I strains were detected infrequently.

Animals↗
PubMed1991

Modelling the analysis of breast cancer screening programmes: sensitivity, lead time and predictive value in the Florence District Programme (1975-1986).

Statistical indicators of early efficacy were estimated in the Florence District Programme where breast cancer screening has been carried out since 1970. Analysis of screen-detected and interval cancer data by means of statistical modelling using GLIM allowed us to estimate the mean sojourn time (1.91 and 3.97 years in 40-49 and 50-69 year old women respectively), sensitivity (about 90% for those aged 50-69) and predictive value at the prevalence screening test (about 100%). Results were compared with estimates of the same parameters in the Health Insurance Plan and Swedish Two County studies.

Adult↗
PubMed1999

Enrichment and efficient screening of ES cells containing a targeted mutation: the use of DT-A gene with the polyadenylation signal as a negative selection maker.

Gene targeting in embryonic stem (ES) cells via homologous recombination can occur at very low frequency. In order to enrich homologous recombinants before screening, a negative selection marker, such as thymidine kinase (TK) and diphtheria toxin A fragment (DT-A), has been commonly used. In this study, we developed a negative selection marker using DT-A gene with polyadenylation signal and it was designated DT-ApA. To determine the difference in targeting efficiency of the negative selections, we constructed three different targeting vectors for each negative selection (first, TK at the 3' end, second, TK at both the 5' and 3' ends < 2 X TK >, and third, DT-ApA at the 5' end of the homologous sequences). Gene targeting experiments using these constructs clearly showed that negative selection using DT-ApA was more efficient than that using TK for homologous recombination and that negative selection using DT-ApA was as efficient as that using 2 X TK. Considering the fact that the use of DT-ApA is more convenient for construction of targeting vectors than that of 2 X TK, DT-ApA is an efficient negative selection marker. In addition, we examined long and accurate PCR (LA-PCR) for screening gene targeted clones. The use of LA-PCR with genomic DNAs from ES cell clones facilitated simple detection of homologous recombinants, suggesting that the screening with LA-PCR is compatible with the use of longer homologous sequences of both arms in vector design. Our results indicate that the use of DT-ApA for negative selection together with the application of LA-PCR for screening ensures efficient and time-saving screening for homologous recombinants.

Animals↗
PubMed2003

Low risk of cervical cancer during a long period after negative screening in the Netherlands.

A condition for effective cervical cancer screening is a low incidence of cervical cancer after negative screening compared to that in the absence of screening. This relative risk was studied for the period 1994-1997 in the Netherlands and compared with previous studies. All cases of invasive cervical cancer diagnosed from 1994 to 1997 in the Netherlands were related to woman-years at risk, stratified by age, number of preceding negative screenings and time since the preceding negative screening. These incidence rates were compared with that before screening started in the Netherlands. The relative risk increases from 0.13 in the first year after screening to 0.24 after more than 6 years after screening for women with one previous negative screening. These figures reduce to 0.06 and 0.18, respectively, for women with two or more previous screenings. However, these estimates are less favourable when account is taken of the likely decrease in risk for cervical cancer in the period studied. Our data show a low relative risk of cervical cancer for several years following the last negative Pap smear. However, the denominator of the relative risk, that is, the incidence without screening, may have been overestimated. This applies also to the IARC multicountry study, and may have caused too optimistic expectations about the effectiveness of cervical cancer screening.

Adult↗
PubMed2001

Predicted long-term mortality reduction associated with the second round of breast screening in East Anglia.

Randomized trials have demonstrated that mammographic screening can reduce breast cancer mortality. Our aim was to estimate the reduction in mortality expected from the East Anglian Breast Screening Programme. Breast screening achieves benefit by improving cancer prognosis (reducing tumour size, nodal involvement and possibly grade) through earlier diagnosis. We compared cancer prognosis between women invited for screening and those not yet invited in East Anglia, UK, in order to predict the mortality reduction achievable by screening, independently of any reduction due to changes in treatment and underlying disease. Participants (both invited and not-yet invited) were women eligible for invitation to first and second screens and diagnosed with invasive breast cancer in 1989-96. Death rates were predicted based on the observed distribution of tumour grade, size and node status amongst 950 cancers diagnosed following first invitation, up to and including at second screen (excluding those detected at first screening), and 451 cancers presenting symptomatically in women awaiting first invitation during the staggered introduction of screening, after adjustment for lead time amongst screen detected cases. For all ages, the ratio of predicted breast cancer mortality in the invited compared with the uninvited group was 0.85 (95% CI 0.78, 0.93). It was 0.93 (0.80, 1.08) for women aged 50-54 at diagnosis and 0.81 (0.72, 0.91) for those aged 55-64. We conclude that, by 2004, the second round of screening in East Anglia should reduce mortality by around 7% in women below age 55 at diagnosis, and by around 19% in those aged 55-64.

Age Factors↗
PubMedDate not supplied

Mass urinary screening and follow-up for school children in Taiwan Province.

Mass urinary screening has been carried out among the students of public and private elementary and junior high schools in the Province of Taiwan each semester since 1990. About 3 million students were screened each time. The students who had abnormal urine screening results at the first time received a second urine analysis 10 to 15 days later to confirm the abnormal urine analysis. The blood samples of the students with abnormal urine examination were taken and biochemistry examinations including creatinine (Cr) etc. were performed since 1992. All students with abnormal urine screening results were graded by the severity of hematuria and proteinuria, the heavy proteinuria graded as "D". Chronic renal failure (CRF) is defined as impaired renal function with the serum Cr over 1.7 mg/dl. Longitudinal continuous blood and urine examinations were performed each semester for the students of grade "D" and with CRF. CRF was confirmed by either the hospital medical records or telephone visit. The purpose of this study was to delineate the prevalence of heavy proteinuria (grade D) and CRF in the students of elementary and junior high school in the Taiwan Province from 1992 to 1996. The results revealed the number of urinary screening was 10,288,620. There were 5980 cases with heavy proteinuria with four-year prevalence of 5.81 x 10(-4), 4.83 x 10(-4) for boys; 6.87 x 10(-4) for girls. Girls were affected more often than boys. The peak age of girls was 12 years old and boys was 13 years old. The number of CRF cases was 189 with the four-year prevalence of 1.84 x 10(-5), 2.24 x 10(-5) for boys; 1.41 x 10(-5) for girls. The incidence rate increased after the age of 10; the peak age of boys being 14-year-old and of girls 12-year-old. The exact contributing factors, such as location on islet or lack of pediatric nephrologist, need further study. In conclusion, the four-year prevalence of heavy proteinuria in the students of the elementary and junior high schools in Taiwan was higher in girls than in boys. Glomerular nephritis (GN) is still one of the major causes of urinary abnormalities. The most-important secondary GN was systemic lupus erythematosus (SLE) with lupus nephritis. The percentage of SLE patients among anti-nuclear antibody (ANA) positive was 72%. In contrast, the four-year prevalence of CRF disease was higher in boys with the peak age at 14-year-old. GN is still the major cause of urinary screening abnormality. ANA study is indicated in all Chinese students with abnormal urinary screening.

Adolescent↗
PubMed2002

Newborn screening: rationale for a comprehensive, fully integrated public health system.

Newborn screening has existed for approximately four decades. During that period of time, newborn screening has evolved conceptually from a laboratory test for a single disorder, phenylketonuria (PKU), to a multi-part public health system involving education, screening, diagnostic follow-up, treatment/management, and system evaluation. At a time when newborn screening is recognized as a model for predictive medicine, it also faces critical challenges that will determine its future credibility and viability. In order to understand these challenges, it is helpful to review briefly the history of newborn screening.

Forecasting↗