ABSTRACT
It is generally presumed that the vast majority of carriers created by chemical doping of semiconducting polymer films are coulombically trapped by the counteranion, with only a small fraction that are free and responsible for the increased conductivity essential for organic electronic applications. At higher doping levels, it is also possible for bipolarons to form, which are expected to be less conductive than single polarons. Unfortunately, there is no simple way to distinguish free polarons, trapped polarons and bipolarons using steady-state spectroscopy. Thus, in this work, we use ultrafast transient absorption spectroscopy to study the dynamics of polarons in 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TNCQ)-doped films of poly(3-hexylthiophene-2,5-diyl) (P3HT) as a function of dopant concentration and excitation wavelength. When exciting on the red side of the polaron P1 transition, our transient absorption spectra and kinetics match well with what is expected for free 2-D-delocalized polarons; the measurements are not consistent with a recent theory of doped conjugated polymer electronic structure that suggests that the half-filled state lies deeper in the conduction band rather than in the bandgap. As we tune the excitation wavelength to the blue, our measurements reveal an increasing amount of slower transient kinetics that are consistent with the presence of coulombically-trapped polarons rather than bipolarons. Taking advantage of their distinct ultrafast relaxation kinetics as a type of action spectroscopy, we are able to extract the steady-state absorption spectra of free and trapped polarons as a function of dopant concentration. By comparing the results to theoretical models, we determine that in F4TCNQ-doped P3HT films, trapped polarons sit â¼0.4 nm away from the anion while free polarons reside between 0.7 and 0.9 nm from the counteranion. Perhaps counterintuitively, the ratio of trapped to free polarons increases at higher doping levels, an observation that is consistent with a plateau in the concentration-dependent conductivity of F4TCNQ-doped P3HT films.
ABSTRACT
BACKGROUND: Research and surveillance work addressing ectopic pregnancy often rely on diagnosis and procedure codes available from automated data sources. However, the use of these codes may result in misclassification of cases. Our aims were to evaluate the accuracy of standard ectopic pregnancy codes; and, through the use of additional automated data, to develop and validate a classification algorithm that could potentially improve the accuracy of ectopic pregnancy case identification. METHODS: Using automated databases from two US managed-care plans, Group Health Cooperative (GH) and Kaiser Permanente Colorado (KPCO), we sampled women aged 15-44 with an ectopic pregnancy diagnosis or procedure code from 2001 to 2007 and verified their true case status through medical record review. We calculated positive predictive values (PPV) for code-selected cases compared with true cases at both sites. Using additional variables from the automated databases and classification and regression tree (CART) analysis, we developed a case-finding algorithm at GH (n = 280), which was validated at KPCO (n = 500). RESULTS: Compared with true cases, the PPV of code-selected cases was 68 and 81% at GH and KPCO, respectively. The case-finding algorithm identified three predictors: ≥ 2 visits with an ectopic pregnancy code within 180 days; International Classification of Diseases, 9th Revision, Clinical Modification codes for tubal pregnancy; and methotrexate treatment. Relative to true cases, performance measures for the development and validation sets, respectively, were: 93 and 95% sensitivity; 81 and 81% specificity; 91 and 96% PPV; 84 and 79% negative predictive value. Misclassification proportions were 32% in the development set and 19% in the validation set when using standard codes; they were 11 and 8%, respectively, when using the algorithm. CONCLUSIONS: The ectopic pregnancy algorithm improved case-finding accuracy over use of standard codes alone and generalized well to a second site. When using administrative data to select potential ectopic pregnancy cases, additional widely available automated health plan data offer the potential to improve case identification.
Subject(s)
Obstetrics/standards , Pregnancy, Ectopic/diagnosis , Adolescent , Adult , Algorithms , Databases, Factual , Diagnosis, Computer-Assisted , Electronic Data Processing , Female , Humans , Medical Records Systems, Computerized , Obstetrics/methods , Predictive Value of Tests , Pregnancy , Reproducibility of ResultsABSTRACT
UNLABELLED: In women age 45 years and older, enrolled in an integrated group practice in 2007, use of ICD9 diagnostic codes, including the "not otherwise specified" code (821.00) resulted in a high false-positive rate for identifying femoral diaphyseal fractures. Restriction to more specific site-codes missed 36% of these rare fractures. INTRODUCTION: The aim of this study was to assess the utility of automated data in identifying the occurrence of femoral diaphyseal fractures. METHODS: We identified all women age 45 years and older enrolled in a Pacific Northwest integrated group practice during 2007. Using the computerized database we selected all ICD9 codes that could be related to a femur fracture occurring in the diaphyseal region. We then quantified the percent of codes confirmed by medical record review to have occurred in the correct anatomic location during the year of interest (positive predictive value). RESULTS: Of the 95,765 eligible women, 161 (0.17%) had an ICD9 diagnostic code potentially related to a femoral diaphyseal fracture in 2007; of these 58 (36%) had a fracture of the femoral diaphysis, and 38 (24%) of the fractures occurred in 2007. The most frequent code was 821.00, described as "femur fracture not otherwise specified", applied to 107 women; 21 of the 58 diaphyseal fractures had this code. CONCLUSION: In this study, use of ICD9 codes that included the "not otherwise specified" code (821.00) resulted in a high false-positive rate for identifying diaphyseal fractures. However, restriction to more specific site codes would have missed at least 36% of the diaphyseal fractures. Furthermore, the codes did not provide any information about the characteristics of the fracture. Our findings support validating cases selected using ICD codes before they are used as a surrogate for the occurrence of femoral diaphyseal fractures.
Subject(s)
Diagnosis, Computer-Assisted/standards , Diaphyses/injuries , Femoral Fractures/diagnosis , International Classification of Diseases/standards , Aged , Aged, 80 and over , Female , Hip Fractures/diagnosis , Humans , International Classification of Diseases/statistics & numerical data , Middle Aged , Northwestern United States , Predictive Value of TestsABSTRACT
Molecular dopants are often added to semiconducting polymers to improve electrical conductivity. However, the use of such dopants does not always produce mobile charge carriers. In this work, ultrafast spectroscopy is used to explore the nature of the carriers created following doping of conjugated push-pull polymers with both F4 TCNQ (2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane) and FeCl3 . It is shown that for one particular push-pull material, the charge carriers created by doping are entirely non-conductive bipolarons and not single polarons, and that transient absorption spectroscopy following excitation in the infrared can readily distinguish the two types of charge carriers. Based on density functional theory calculations and experiments on multiple push-pull conjugated polymers, it is argued that the size of the donor push units determines the relative stabilities of polarons and bipolarons, with larger donor units stabilizing the bipolarons by providing more area for two charges to co-reside.
ABSTRACT
Despite the fact that molecular doping of semiconducting polymers has emerged as a valuable strategy for improving the performance of organic electronic devices, the fundamental dopant-polymer interactions are not fully understood. Here we use 2-D grazing incidence wide-angle X-ray scattering (GIWAXS) to demonstrate that adding oxidizing small-molecule dopants, such as 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) and FeCl3, into the amorphous conjugated polymer, regiorandom poly(3-hexylthiophene-2,5-diyl) (RRa-P3HT), improves polymer ordering and induces a change in domain orientation from isotropic to mostly edge-on. Doping thus causes RRa-P3HT to behave similarly to the more ordered regioregular P3HT. By comparing the optical, electrical, and structural properties of RRa-P3HT films doped with F4TNCQ and FeCl3 and those infiltrated with 7,7,8,8-tetracyanoquinodimethane (TCNQ), which occupies a similar volume as F4TCNQ but does not dope RRa-P3HT, we show that the increased ordering results not from the ability of the dopant to fill space but instead from the need to delocalize charge on the polymer in more than one dimension.
ABSTRACT
UNLABELLED: In this clinical trial of 12.5 or 25 mg/day of hydrochlorothiazide, the urine calcium showed significant decreases from placebo in men at one year, but the effects had waned by 3 years. Serum bicarbonate was consistently greater in the thiazide than in the placebo groups throughout the three years. These effects could be beneficial to the skeleton. INTRODUCTION: Previous studies have shown increased bone density and reduced risk of fracture in patients taking thiazide diuretics. The long-term effects of low-dose thiazides on mineral metabolism have not been reported in normal subjects. METHODS: We conducted a randomized, double-blinded trial in normals aged 60-79 years, using hydrochlorothiazide 12.5 or 25 mg/d or placebo for three years. Subjects were encouraged to maintain calcium intake of 1,000 to 1,500 mg/day. Measurements of serum and urine calcium metabolism were done at baseline, six months, and yearly. Data were analyzed in 88 men and 177 women who had taken study medication. Adjusted change in the measurements from baseline to one and three years were compared among groups. RESULTS: The calcium intake increased in all groups. Urine calcium per day was significantly lower in thiazide than placebo groups in men at one year but not at three years; in women the changes were not significantly different. Serum bicarbonate was higher in thiazide compared to placebo groups at one and three years. No changes were seen in serum calcium, phosphate, parathyroid hormone, sodium or magnesium. CONCLUSIONS: The results suggest that both increased calcium availability from a hypocalciuric effect and reduction in acid-induced bone buffering could be mechanisms for the beneficial skeletal effects.
Subject(s)
Bone Density/drug effects , Bone and Bones/metabolism , Hydrochlorothiazide/pharmacology , Minerals/metabolism , Aged , Bicarbonates/blood , Bone Density/physiology , Bone Resorption/prevention & control , Bone and Bones/drug effects , Calcium/urine , Calcium, Dietary/administration & dosage , Dose-Response Relationship, Drug , Double-Blind Method , Drug Administration Schedule , Female , Humans , Hydrochlorothiazide/administration & dosage , Male , Middle Aged , Sex FactorsABSTRACT
Two hundred nine female enrollees of the Group Health Cooperative of Puget Sound who developed advanced-stage breast cancer during the period 1982-1988 were interviewed about their practice of breast self-examination (BSE), use of other breast cancer screening modalities, and medical and reproductive histories. Each subject's description of how she performed the examination was scored according to her mention of up to 10 recommended BSE techniques. A random sample of 433 women without advanced-stage breast cancer from the same population was interviewed for comparison. Relative to women not practicing BSE, the risk of advanced-stage breast cancer among BSE users was 1.15 (95% confidence interval, 0.73-1.81). Frequency of BSE did not differ between women with advanced-stage breast cancer and control subjects, whether in all subjects or in subgroups defined by age, use of mammography, or frequency of clinical breast examinations. While self-described proficiency in BSE was generally low in both case and control subjects, the small percentage of women reporting more thorough self-examinations, regardless of frequency, had about a 35% decrease in the occurrence of advanced-stage breast cancer compared to women who did not perform BSE. These results suggest that, while carefully performed BSE may avoid the development of some advanced-stage breast cancers, BSE as practiced by most Seattle-area women is of little or no benefit.
Subject(s)
Breast Neoplasms/diagnosis , Self-Examination , Adult , Aged , Aged, 80 and over , Breast Neoplasms/epidemiology , Case-Control Studies , Evaluation Studies as Topic , Female , Humans , Middle Aged , Neoplasm Staging , Risk FactorsABSTRACT
A plant's compensatory performance refers to its ability to maintain or increase its reproductive output following damage. The ability of a plant to compensate depends on numerous factors including the type, severity, frequency and timing of damage, the environmental conditions and the plant's genotype. Upon apical damage, a cascade of hormonal and genetic responses often produces dramatic changes in a plant's growth, development, architecture and physiology. All else being equal, this response is largely dependent on a plant's genotype, with different regrowth patterns displayed by different genotypes of a given species. In this study, we compare the architectural and growth patterns of two Arabidopsis thaliana genotypes following apical damage. Specifically, we characterise regrowth patterns of the genotypes Columbia-4 and Landsberg erecta, which typically differ in their compensation to apical meristem removal. We report that Landsberg erecta suffered reductions in the number of stems produced, maximum elongation rate, a delay in reaching this rate, lower average rosette quality throughout the growing period, and ultimately, less aboveground dry biomass and seed production when damaged compared to undamaged control plants. Columbia-4 had no reductions in any of these measures and maintained larger rosette area when clipped relative to when unclipped. Based on the apparent influence of the rosette on these genotypes' compensatory performances, we performed a rosette removal experiment, which confirmed that the rosette contributes to compensatory performance. This study provides a novel characterisation of regrowth patterns following apical damage, with insights into those measures having the largest effect on plant performance.
Subject(s)
Arabidopsis/growth & development , Arabidopsis/genetics , Plant Leaves/growth & development , Biomass , Genotype , Phenotype , Plant Stems/genetics , Plant Stomata/growth & developmentABSTRACT
Small-cell lung carcinoma (SCLC) is a rapidly progressive and fatal disease. Historically, surgical resection or radiotherapy of the primary tumor has done little to prolong survival, although the use of combination chemotherapy is more effective. Reported here is the survival experience of 1,538 incident cases of SCLC identified through the Surveillance, Epidemiology and End Results Program in western Washington State from 1974 to 1982. The survival experience of this population series is similar to that reported from specialized referral centers. For 71 of 78 persons surviving at least 24 months, the original diagnostic slides were independently reviewed, 47 cases being confirmed as SCLC. No differences were found in actuarial survival estimates between those confirmed and those not confirmed as SCLC. Multivariate survival analysis was conducted to estimate the effects on survival of stage, therapy, age, sex, primary site, and histologic type. All factors except primary site and histologic type significantly influence initial survival rates. However, the only factor related to post--two-year (ie, long-term) survival, once stage is accounted for, is whether surgery was received as a first course of therapy. Those not receiving surgery were at four times the risk of death as those who did. These results indicate that long-term survival can be achieved in patients with SCLC treated in the community, and that the chance of surviving an additional two years for such patients is approximately 40%.
Subject(s)
Carcinoma, Small Cell/mortality , Lung Neoplasms/mortality , Adult , Age Factors , Carcinoma, Small Cell/pathology , Carcinoma, Small Cell/therapy , Female , Humans , Lung Neoplasms/pathology , Lung Neoplasms/therapy , Male , Middle Aged , Neoplasm Metastasis , Population Surveillance , Prognosis , Sex Factors , Time FactorsABSTRACT
Most Ty1 retrotransposons in the genome of Saccharomyces cerevisiae are transpositionally competent but rarely transpose. We screened yeast mutagenized by insertion of the mTn3-lacZ/LEU2 transposon for mutations that result in elevated Ty1 cDNA-mediated mobility, which occurs by cDNA integration or recombination. Here, we describe the characterization of mTn3 insertions in 21 RTT (regulation of Ty1 transposition) genes that result in 5- to 111-fold increases in Ty1 mobility. These 21 RTT genes are EST2, RRM3, NUT2, RAD57, RRD2, RAD50, SGS1, TEL1, SAE2, MED1, MRE11, SCH9, KAP122, and 8 previously uncharacterized genes. Disruption of RTT genes did not significantly increase Ty1 RNA levels but did enhance Ty1 cDNA levels, suggesting that most RTT gene products act at a step after mRNA accumulation but before cDNA integration. The rtt mutations had widely varying effects on integration of Ty1 at preferred target sites. Mutations in RTT101 and NUT2 dramatically stimulated Ty1 integration upstream of tRNA genes. In contrast, a mutation in RRM3 increased Ty1 mobility >100-fold without increasing integration upstream of tRNA genes. The regulation of Ty1 transposition by components of fundamental pathways required for genome maintenance suggests that Ty1 and yeast have coevolved to link transpositional dormancy to the integrity of the genome.
Subject(s)
Genome , Retroelements/genetics , Saccharomyces cerevisiae/metabolism , Blotting, Northern , DNA Damage , DNA, Complementary/metabolism , Genes, Fungal , Models, Genetic , Mutagenesis , Mutation , Plasmids/metabolism , RNA/metabolism , Retroelements/physiology , Telomere/metabolism , Transcription, GeneticABSTRACT
BACKGROUND: Staphylococcus saprophyticus is the second most common cause of urinary tract infection (UTI) in young women. Relatively little is known about risk factors for this infection including exposure to vaginal spermicides, which increases the risk of UTI caused by Escherichia coli. PATIENTS AND METHODS: We conducted a case-control study in a large health maintenance organization Case patients were sexually active young women with acute UTIs caused by S saprophyticus identified from computerized laboratory files during 1990 to 1993. Population-based control patients were randomly selected from the organization's enrollment files. Exposures such as sexual activity and contraceptive practice were determined by interview. RESULTS: Of 1299 eligible women, 66% (96 case patients and 629 control patients) were interviewed. Case patients were more often unmarried and were more sexually active. Ninety-nine percent of case patients and 57% of control patients reported previous UTIs. Exposure to any type of condom during the previous year was reported by 53% of case patients and 31% of control patients. Exposure to spermicide-coated condoms during the previous month was associated with a higher risk of UTI (odds ratio [OR], 3.8; 95% confidence interval, 1.4-10.3). The OR for exposure during the previous year ranged from 2.2 (95% confidence interval, 1.0-4.8) for less than once weekly to 6.05 (95% confidence interval, 2.2-16.6) for more than twice weekly. In multivariate analyses, younger age (OR, 0.97 per year), intercourse frequency (OR, 1.2 per weekly episode), prior UTI (OR, 3.3), and frequency of exposure to spermicide-coated condoms (OR, 8.4 for more than once weekly and 10.9 for more than twice weekly) were independent predictors of UTI. Among women exposed to spermicide-coated condoms, 74% of UTIs caused by S saprophyticus were attributable to this exposure. CONCLUSIONS: Spermicide-coated condoms were associated with an increase risk of UTI caused by S saprophyticus. Because sexual activity and spermicide exposure are important risk factors for UTI caused by both S saprophyticus and E coli, it is likely that they share a similar pathogenesis.
Subject(s)
Condoms/adverse effects , Spermatocidal Agents/adverse effects , Staphylococcal Infections/microbiology , Urinary Tract Infections/etiology , Urinary Tract Infections/microbiology , Case-Control Studies , Female , Humans , Male , Odds Ratio , Risk FactorsABSTRACT
Although it is known that evaporated metals can penetrate into films of various organic molecules that are a few nanometers thick, there has been little work aimed at exploring the interaction of the common electrode metals used in devices with fullerene derivatives, such as organic photovoltaics (OPVs) or perovskite solar cells that use fullerenes as electron transport layers. In this paper, we show that when commonly used electrode metals (e.g., Au, Ag, Al, Ca, etc.) are evaporated onto films of fullerene derivatives (such as [6,6]-phenyl-C61-butyric acid methyl ester (PCBM)), the metal penetrates many tens of nanometers into the fullerene layer. This penetration decreases the effective electrical thickness of fullerene-based sandwich structure devices, as measured by the device's geometric capacitance, and thus significantly alters the device physics. For the case of Au/PCBM, the metal penetrates a remarkable 70 nm into the fullerene, and we see penetration of similar magnitude in a wide variety of fullerene derivative/evaporated metal combinations. Moreover, using transmission electron microscopy to observed cross-sections of the films, we show that when gold is evaporated onto poly(3-hexylthiophene) (P3HT)/PCBM sequentially processed OPV quasi-bilayers, Au nanoparticles with diameters of â¼3-20 nm are formed and are dispersed entirely throughout the fullerene-rich overlayer. The plasmonic absorption and scattering from these nanoparticles are readily evident in the optical transmission spectrum, demonstrating that the interpenetrated metal significantly alters the optical properties of fullerene-rich active layers. This opens a number of possibilities in terms of contact engineering and light management so that metal penetration in devices that use fullerene derivatives could be used to advantage, making it critical that researchers are aware of the electronic and optical consequences of exposing fullerene-derivative films to evaporated electrode metals.
Subject(s)
Electrochemistry/instrumentation , Fullerenes/chemistry , Metals/chemistry , Nanostructures/chemistry , Electricity , Electrodes , Esters/chemistry , Nanostructures/ultrastructure , Semiconductors , VolatilizationABSTRACT
We demonstrate that solution-sequential processing (SqP) can yield heavily doped pristine-quality films when used to infiltrate the molecular dopant 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) into pure poly(3-hexylthiophene) (P3HT) polymer layers. Profilometry measurements show that the SqP method produces doped films with essentially the same surface roughness as pristine films, and 2-D grazing-incidence wide-angle X-ray scattering (GIWAXS) confirms that SqP preserves both the size and orientation of the pristine polymer's crystallites. Unlike traditional blend-cast F4TCNQ/P3HT doped films, our sequentially processed layers have tunable and reproducible conductivities reaching as high as 5.5 S/cm even when measured over macroscopic (>1 cm) distances. The high conductivity and superb film quality allow for meaningful Hall effect measurements, which reveal p-type conduction and carrier concentrations tunable from 10(16) to 10(20) cm(-3) and hole mobilities ranging from â¼0.003 to 0.02 cm(2) V(-1) s(-1) at room temperature over the doping levels examined.
ABSTRACT
The purpose of this study was to compare biochemical markers of bone resorption and formation in young women using different hormonal contraceptive methods. Women aged 18-39 yr who were using depot medroxyprogesterone acetate (DMPA) contraception were recruited for the study; comparison women were matched by age and clinic location. There were 116 women using DMPA, 39 using oral contraceptives containing estrogen and progestin, and 72 not currently using hormonal contraceptives. Biochemical measurements were serum calcium, PTH and osteocalcin, and urine N-telopeptide. Bone density was measured using dual-energy x-ray absorptiometry. The N-telopeptide levels, adjusted for age and other risk factors, were 42.4 +/- 2.3 nmol/mmol creatinine in the DMPA group, 26.2 +/- 3.3 nmol/mmol in the oral contraceptive group, and 35.4 +/- 2.9 nmol/mmol in the nonusers; significant differences were seen in all pairwise comparisons. Osteocalcin levels showed the same pattern, although the difference between the DMPA users and nonusers was not statistically significant. There were no differences among groups in the PTH levels. The bone density at the spine was 1.086 +/- 0.085 g/cm(2) in the DMPA group, 1.103 +/- 0.095 g/cm(2) in the oral contraceptive group, and 1.093 +/- 0.090 g/cm(2) in nonusers (P = 0.051). The results suggest that in women using DMPA bone resorption exceeded bone formation.
Subject(s)
Bone and Bones/metabolism , Contraceptive Agents, Female/pharmacology , Medroxyprogesterone Acetate/pharmacology , Adult , Biomarkers , Bone Density/drug effects , Bone Resorption/metabolism , Bone and Bones/drug effects , Contraceptive Agents, Female/adverse effects , Contraceptives, Oral/pharmacology , Delayed-Action Preparations , Estrogens/pharmacology , Female , Humans , Medroxyprogesterone Acetate/adverse effects , Osteocalcin/blood , Osteogenesis/drug effects , Premenopause/metabolism , Progestins/pharmacologyABSTRACT
Histamine (H2) receptor antagonists, such as cimetidine and ranitidine, became available in the late 1970s and presently number among the most commonly used drugs. Cimetidine has been hypothesized to exert a cancer preventive effect on the prostate due to its ability to inhibit the binding of dihydrotestosterone to androgen receptors. Other hormonal effects of this drug include increases in serum prolactin levels and inhibition of 2-hydroxylation of estradiol. We assessed risk of prostate and breast cancers in a cohort of 48,512 members of the Group Health Cooperative of Puget Sound prescribed cimetidine or another H2 blocker between 1977 and 1995. Standardized incidence ratios were calculated comparing the observed numbers of cancers to those expected based on population rates in western Washington State. Because cimetidine, but not other H2 blockers, influences hormonal activity and metabolism, we conducted nested case-control studies comparing cancer risk among individuals treated with cimetidine to individuals who used other H2 blockers. Risks of breast and prostate cancers were identical among users of cimetidine and users of other H2 blockers (relative risk, 1.0 for both cancers). We observed no trend in risk of breast cancer according to time since first or last cimetidine prescription or number of cimetidine prescriptions filled. For prostate cancer, our findings were similar save for a modest increase in risk among men who had filled > or =21 cimetidine prescriptions (relative risk, 1.4; 95% confidence interval, 1.0-1.9). Our results suggest that use of cimetidine does not influence risk of female breast cancer. Further, these data provide little evidence to support the previously hypothesized preventive effect of cimetidine on risk of prostate cancer.
Subject(s)
Breast Neoplasms/etiology , Cimetidine/adverse effects , Histamine H2 Antagonists/adverse effects , Prostatic Neoplasms/etiology , Adult , Aged , Aged, 80 and over , Breast Neoplasms/epidemiology , Case-Control Studies , Female , Humans , Incidence , Male , Middle Aged , Prostatic Neoplasms/epidemiology , Risk AssessmentABSTRACT
PURPOSE: Acute uncomplicated urinary tract infection is a common and costly disorder in women. To reduce potentially unnecessary expense and inconvenience, a large staff-model health maintenance organization instituted a telephone-based clinical practice guideline for managing presumed cystitis in which women 18 to 55 years of age who met specific criteria were managed without a clinic visit or laboratory testing. We sought to evaluate the effects of the guideline. SUBJECTS AND METHODS: We performed a population-based, before-and-after study with concurrent control groups at 24 primary care clinics to assess the effect of guideline implementation on resource utilization and on the occurrence of potential adverse outcomes. We measured the proportion of patients with presumed uncomplicated cystitis who had a return office visit for cystitis or sexually transmitted disease or who developed pyelonephritis within 60 days of the initial diagnosis. Relative risks (RR) and 95% confidence intervals (CI) were estimated, adjusting for the effects of clustering within clinics. RESULTS: A total of 3,889 eligible patients with presumed acute uncomplicated cystitis were evaluated. As compared with baseline, guideline implementation significantly decreased the proportion of patients with presumed cystitis who received urinalysis (RR = 0.75; CI, 0.70 to 0.80), urine culture (RR = 0.73; CI, 0.68 to 0.79), and an initial office visit (RR = 0.67; CI, 0.62 to 0.73), while increasing the proportion who received a guideline-recommended antibiotic 2.9-fold (CI, 2.4 to 3.7-fold). In the prospective comparison of the 22 intervention and two control clinics, the guideline decreased the proportion of patients who had urinalyses performed (RR = 0.80; CI, 0.65 to 0.98) and increased the proportion of patients who were prescribed a guideline-recommended antibiotic (RR = 1.53; CI, 1.01 to 2.33). Adverse outcomes did not increase significantly in either comparison. CONCLUSION: Guideline use decreased laboratory utilization and overall costs while maintaining or improving the quality of care for patients who were presumptively treated for acute uncomplicated cystitis.
Subject(s)
Health Maintenance Organizations/statistics & numerical data , Urinary Tract Infections/diagnosis , Urinary Tract Infections/therapy , Adult , Case-Control Studies , Cystitis/complications , Cystitis/diagnosis , Cystitis/therapy , Female , Humans , Middle Aged , Office Visits/statistics & numerical data , Outcome Assessment, Health Care , Practice Guidelines as Topic , Pyelonephritis/diagnosis , Pyelonephritis/etiology , Pyelonephritis/therapy , Telephone , WashingtonABSTRACT
OBJECTIVE: To increase our understanding of the factors that impede or promote counseling about hormone replacement therapy, we asked clinicians to provide information concerning barriers and strategies to promote counseling. DESIGN: We asked clinicians to consider two different scenarios: (1) what they do in they current practice and (2) what they would do if their health care systems implemented the United States Preventive Services Task Force recommendation regarding hormone replacement therapy counseling. A total of 49 of 50 invited clinicians participated in one of six focus group interviews (three women's groups and three men's groups). Our analysis consisted of four steps: (1) identifying segments and classifying them into themes, (2) categorizing themes into topic areas, (3) establishing a final consensus of themes and topics, and (4) ascertaining similarities and contrasts among groups. Transcripts of sessions were analyzed across groups for themes using a text-based analysis system. Conceptualization of themes was derived using a system model of preventive care. Interrater agreement before consensus was good: Kappa (kappa) ranged from 0.70 to 1.00. RESULTS: For current practice, identified barriers included lack of information about risks and benefits, unique challenges of counseling, and lack of resources to conduct counseling. The major strategies suggested were to develop and distribute patient education materials. Discussions about barriers to implementing the United States Task Force recommendation focused on lack of information and resources. CONCLUSIONS: Suggested strategies were multiple, involving individual-, relationship-, and system-level interventions. We expect the strategies identified to be supportive of future efforts to promote counseling for hormone replacement therapy.
Subject(s)
Counseling/methods , Health Knowledge, Attitudes, Practice , Hormone Replacement Therapy , Physicians, Women , Primary Health Care , Counseling/trends , Data Collection , Decision Making , Female , Focus Groups , Humans , Male , Patient Education as Topic , Practice Patterns, Physicians' , Sex Factors , United StatesABSTRACT
OBJECTIVE: To assess the prevalence, amount, and duration of use of vaginal estrogen cream among several birth cohorts of women from 1983 through 1992. DESIGN: Analyses are based on automated membership, pharmacy, and hospital discharge databases from Group Health Cooperative (GHC) of Puget Sound, a large health maintenance organization in Seattle, Washington. PARTICIPANTS: A total of 33,822 women, aged 45 years and older as of December 31, 1983, who were enrolled in GHC from 1983 to 1992 or who were enrolled at baseline and died in the following decade. RESULTS: About 24% of the cohort had filled at least one prescription for vaginal estrogen cream during 1983 through 1992, and about 60% of the users had more than one prescription filled. The annual birth cohort-specific prevalence of having filled one or more prescriptions for vaginal estrogen creams ranged between 1.6 and 8.2% across birth cohorts, whereas the average annual prevalence for the cohort was between 5.3 and 6.8%. The total amount, duration of use, and proportion of total estrogen exposure from creams increased with age of the birth cohort. Among the 733 women with intact uteri who were long-term cream users, 60.4% had no progestin prescriptions while averaging 22.1 tubes of estrogen cream. CONCLUSION: The prescription-filling patterns for estrogen in this cohort show an increase in the amount, years of use, and proportion of estrogen exposure from creams with the age of the birth cohort and extensive unopposed cream use among a small proportion of women with intact uteri. The systemic effects of vaginal estrogen cream among older postmenopausal women with urogenital atrophy deserve closer scrutiny.
Subject(s)
Drug Prescriptions/statistics & numerical data , Estrogens/therapeutic use , Women , Administration, Oral , Age Factors , Aged , Aged, 80 and over , Cohort Studies , Drug Utilization/statistics & numerical data , Drug Utilization/trends , Female , Health Maintenance Organizations , Humans , Hysterectomy/statistics & numerical data , Middle Aged , Progestins/therapeutic use , Survival Analysis , Time Factors , Vaginal Creams, Foams, and Jellies , WashingtonABSTRACT
OBJECTIVE: To determine whether 1) women smokers are aware that smoking increases their risk for cervical cancer; 2) awareness of risk factors and its impact on motivation to quit smoking vary by age; and 3) providers are advising smokers to quit smoking during routine gynecologic visits. METHODS: Women aged 18 years and older who had a Papanicolaou test in the prior month were identified from a managed care cytology database. Four weeks after receiving their test result, women were called to complete a health behavior survey in which their smoking status, sexual history, knowledge of risk factors for cervical cancer, and motivation to quit smoking were assessed. RESULTS: Only 49% of the 613 smokers surveyed were aware that smoking increased their risk of cervical cancer. Women aged 34 years and younger were significantly more likely to agree that smoking increased their risk for cervical cancer than women aged 45 years or older (54% versus 40%). Concern that smoking might cause cervical cancer or other cancers was endorsed highly by women as a motivator for cessation, particularly for women smokers aged 18-26 (mean 8.1 and 7.6 on 10-point scales, respectively). About 50% of the women reported that their provider had asked about smoking and had encouraged cessation. Only about 30% of smokers were aware of well-established risk factors for cervical cancer such as the number of lifetime sexual partners and not using a condom. CONCLUSION: Routine gynecologic screening visits represent an important and underutilized clinical opportunity to intervene with young women smokers.
Subject(s)
Health Education , Smoking Cessation , Uterine Cervical Neoplasms/diagnosis , Adolescent , Adult , Female , Humans , Middle Aged , Motivation , Papanicolaou Test , Risk Factors , Smoking/adverse effects , Smoking Cessation/psychology , Uterine Cervical Neoplasms/etiology , Vaginal SmearsABSTRACT
OBJECTIVE: To evaluate the association between vaginal douching and cervical Chlamydia trachomatis infection. METHODS: We analyzed cross-sectional data from a study conducted at Group Health Cooperative of Puget Sound, a nonprofit health maintenance organization in western Washington state. Participants were nonpregnant women Group Health enrollees between the ages of 18 and 34 years who were attending two primary care clinics either for nonurgent visits, primarily routine preventive health visits, or in response to an invitation from the study. Before the clinical examination, all completed a self-administered survey assessing demographic and behavioral characteristics, including the timing, frequency, products used, and reasons for douching. Chlamydial infection was ascertained via cell culture isolation of C trachomatis from endocervical specimens obtained at the same visit. RESULTS: Chlamydia trachomatis was isolated from cervical cultures in 58 (3.4%) of 1692 study participants. Women who reported douching in the 12 months before their clinic visit had an increased likelihood of chlamydial infection compared with women who did not douche (prevalence odds ratio [OR] 2.29, 95% confidence interval [CI] 1.22, 4.30, after adjusting for confounding factors). The likelihood was higher for women who reported douching more often: OR 2.60 (95% CI 1.29, 5.24) for women who douched one to three times per month, and OR 3.84 (95% CI 1.26, 11.70) for those douching four times or more per month. These associations were slightly stronger when women who reported douching because of an infection were excluded from the analysis. CONCLUSION: These results support the hypothesis that vaginal douching predisposes to acquisition of cervical chlamydial infection and are compatible with previous studies that report associations between douching and sequelae of chlamydial infection, including pelvic inflammatory disease, ectopic pregnancy, and infertility.