Spherical-angular dark field imaging and sensitive microstructural phase clustering with unsupervised machine learning.

Electron backscatter diffraction is a widely used technique for nano- to micro-scale analysis of crystal structure and orientation. Backscatter patterns produced by an alloy solid solution matrix and its ordered superlattice exhibit only extremely subtle differences, due to the inelastic scattering that precedes coherent diffraction. We show that unsupervised machine learning (with principal component analysis, non-negative matrix factorisation, and an autoencoder neural network) is well suited to fine feature extraction and superlattice/matrix classification. Remapping cluster average patterns onto the diffraction sphere lets us compare Kikuchi band profiles to dynamical simulations, confirm the superlattice stoichiometry, and facilitate virtual imaging with a spherical solid angle aperture. This pipeline now enables unparalleled mapping of exquisite crystallographic detail from a wide range of materials within the scanning electron microscope.

Advancing characterisation with statistics from correlative electron diffraction and X-ray spectroscopy, in the scanning electron microscope.

The routine and unique determination of minor phases in microstructures is critical to materials science. In metallurgy alone, applications include alloy and process development and the understanding of degradation in service. We develop a correlative method, exploring superalloy microstructures, which are examined in the scanning electron microscope (SEM) using simultaneous energy dispersive X-ray spectroscopy (EDS) and electron backscatter diffraction (EBSD). This is performed at an appropriate length scale for characterisation of carbide phases' shape, size, location, and distribution. EDS and EBSD data are generated using two different physical processes, but each provide a signature of the material interacting with the incoming electron beam. Recent advances in post-processing, driven by 'big data' approaches, include use of principal component analysis (PCA). Components are subsequently characterised to assign labels to a mapped region. To provide physically meaningful signals, the principal components may be rotated to control the distribution of variance. In this work, we develop this method further through a weighted PCA approach. We use the EDS and EBSD signals concurrently, thereby labelling each region using both EDS (chemistry) and EBSD (crystal structure) information. This provides a new method of amplifying signal-to-noise for very small phases in mapped regions, especially where the EDS or EBSD signal is not unique enough alone for classification.

Risk of morbidity following catheter removal among neonates with catheter associated bloodstream infection.

OBJECTIVE: We hypothesized that infectious morbidities following percutaneously inserted central venous catheter (PICC) removal would be greater among neonates with central-line associated bloodstream infection (CLBASI). STUDY DESIGN: This retrospective cohort study, included all neonates who required a PICC over a ten-year period. Outcomes assessed following PICC removal included: late bloodstream infection, rule-out sepsis workups, need for a subsequent PICC and antibiotic days and PICC days after PICC removal. Odds ratios (OR) and 95% confidence intervals (CI) were determined for outcomes. Regression analyses were used to control for confounders. RESULTS: Two-thousand nine hundred and thirteen neonates required at least one PICC during the study period. After adjusting for confounders neonates with CLABSI were 3.4 (95% confidence interval (CI) 2.5, 4.6) and 2.2 (95% CI 1.2, 4.0) times more likely respectively to require a subsequent PICC or develop a late bloodstream infection after PICC removal. Neonates with CLABSI required 1.33 (95% CI 0.77, 1.89) more days of antibiotic treatment and 6.85 (95% CI 5.34, 8.37) more PICC days following PICC removal than neonates without a CLABSI. CONCLUSIONS: Neonates with CLABSI are at risk for additional infectious morbidities after PICC removal. Future intervention studies aimed at reducing CLABSI should evaluate whether morbidities following catheterization are also reduced.

Programmes, resources, and needs of HIV-prevention nongovernmental organizations (NGOs) in Africa, Central/Eastern Europe and Central Asia, Latin America and the Caribbean.

This study assessed the programmes, resources, and needs of HIV-prevention nongovernmental organizations (NGOs) in 75 countries in Africa, Central/Eastern Europe and Central Asia, Latin America and the Caribbean. Multiple databases and expert recommendations were used to identify one major HIV-prevention NGO in the capital or a large city in each country, and in-depth interviews were conducted with each NGO Director. Most NGOs are carrying out their programmes with minimal funding and few regularly employed personnel. Most are highly dependent on international donors, but reliance on small grants with short funding periods limits programme development capacity. HIV-prevention activities varied by region, with African NGOs most likely to use peer education and community awareness events; Eastern European NGOs most likely to offer needle exchange; Latin American NGOs to have resource centres and offer risk reduction programmes; and Caribbean organizations to use mass education approaches. Across regions, NGOs most often targeted the general public and youth, although specialized at-risk groups were the additional focus of attention in some regions. Limited funding, governmental indifference or opposition, AIDS stigma, and social discomfort discussing sex were often cited as barriers to new HIV-prevention programmes. NGOs are critical service providers. However, their funding, programmes, and resource capacities must be strengthened if NGOs are to realize their full potential in HIV prevention.

Number of repetitions to maximum in hop tests in patients with anterior cruciate ligament injury.

The unilateral horizontal, triple cross-over and vertical hops are commonly used as outcome measures after knee injury but there is little knowledge of the number of repetitions needed to reach maximum performance. Seventy subjects who had either an anterior cruciate ligament deficient or reconstructed knee participated in this study. Unilateral vertical, horizontal, and triple cross-over hop testing was applied to each leg until two consecutive decrements in performance occurred. The number of repetitions to reach maximum during these tests were calculated. Fifteen repetitions of the horizontal and vertical hops, and 10 repetitions of the triple-crossover hop enable distances to be achieved that are acceptably close to maximal levels in these knee-injured patients. In order to increase the likelihood of finding a patient's maximum hop performance after knee injury, more repetitions are suggested than has been reported in the literature.

Identifying, recruiting, and assessing social networks at high risk for HIV/AIDS: methodology, practice, and a case study in St Petersburg, Russia.

Population segments at highest risk for HIV are often hidden, marginalized, and hard to reach by conventional prevention programmes. This pattern is especially true in Central and Eastern Europe, where major HIV epidemics have recently appeared, where population members do not perceive themselves as belonging to a community, and where there is little precedence for strong community-based organization service programmes. In these circumstances, naturally existing intact social networks still can be targeted by prevention programmes. HIV prevention interventions undertaken with at-risk social networks can establish new group norms, reduce the risk behaviour of network members, and can reach 'hidden' members of a population known personally to leaders of the social networks. This article illustrates a methodology and a practical description for: (1) accessing high-risk social networks in a community population; (2) identifying and enumerating the membership of the social networks; (3) identifying the social leadership of the networks; and (4) establishing the HIV risk behaviour levels of the recruited networks. To illustrate how social network methods can be applied in the field, the article provides case study reports of HIV prevention fieldwork practice targeting high-risk networks of young men who have sex with men and young heterosexual adults in St Petersburg, Russia. Although there is an extensive conceptual literature on the influence of social networks on risk behaviour, this article describes specific and practical techniques that can be in the development of approaches for social network-based interventions.

HIV risk characteristics and prevention needs in a community sample of bisexual men in St. Petersburg, Russia.

A new and understudied HIV epidemic is quickly unfolding in the Central and Eastern European countries of the former Soviet Union. Men who have sex with men (MSM) in Russia constitute a population highly vulnerable to sexually-transmitted HIV infection. In a community sample of 434 Russian MSM accessed in gay venues in St. Petersburg, 126 had had both male and female partners in the past three months. In this paper, we report on their risk characteristics. Forty-five per cent of men reported recently engaging in unprotected anal intercourse with their male partners. Respondents had a mean of 3.3 male and 3.4 female partners in the past three months, and most had multiple male and female partners in this time period. There were serious and significant gaps in the AIDS risk knowledge levels of these men, and most believed they had no personal contact with HIV-positive people. Bisexual men were more likely than exclusively gay men to have engaged in commercial sex and tended to have lower AIDS risk knowledge. Although they did not differ in average age, bisexual compared to gay men more recently had their first sex with a man. Multivariate logistic and linear regression analyses showed that condom and safer sex attitudes, perceived norms, AIDS risk knowledge and age at first sex with a man were independent predictors of high-risk behaviour among bisexual men. HIV prevention interventions for bisexual men should address their sexual practices with both male and female partners, correct misconceptions about risk, address behaviour practices rather than gay identity, and recognize risk issues faced by the female partners of bisexual men.

Identification of candidate genes in ulcerative colitis and Crohn's disease using cDNA array technology.

Inflammatory bowel disease (IBD) follows a multigenic mode of inheritance, encompassing the clinically discrete phenotypes of ulcerative colitis (UC) and Crohn's disease (CD). The risk of malignant transformation of the colon increases with the duration and extent of IBD and is particularly high for patients with a longstanding history of UC. We wished to identify candidate genes that might be involved in disease pathogenesis based on functional plausibility and their putative role in IBD carcinogenesis. Polyadenylated mRNA (PolyA+ mRNA) preparation from inflamed intestinal mucosa of patients with a longstanding history of UC and CD was performed with subsequent hybridization of alpha phosphorus [alpha-32P]-deoxyadenotriphosphate-labeled complementary deoxyribonucleic acid (DNA) populations to nucleic acid arrays. Of 588 different human gene transcripts arrayed, secreted apoptosis-related protein 1 (Sarp1), frizzled (fz) homologues, and disheveled (dvl) were differentially expressed, being elevated in UC as compared to CD. These genes encode proteins involved in the Wingless-type (Wnt)/beta-catenin signaling pathway. The autonomous expression of Sarp1 and Sarp1-compatible fz receptor genes suggests that the Wnt pathway may be involved in UC carcinogenesis.

Validation of the Hughston Clinic subjective knee questionnaire using gait analysis.

INTRODUCTION: Subjective questionnaires, completed by the patient, are often used to document the status of a disabled knee. The purpose of this study was to validate the Hughston Clinic subjective knee questionnaire by describing how knee kinematics and kinetics correlated to subjective knee scores after knee injury and surgery. METHODS: Five groups were studied: patients 2 (N = 37), 6 (N = 37), and 24 (N = 8) wk after ACL reconstruction (ACLR); patients with a chronic PCL deficiency (N = 9); and uninjured controls (N = 8). A three-dimensional motion analysis system and force platform were used to measure flexion angles and knee moments during level walking and stair climbing. RESULTS: Hughston Clinic questionnaire scores were significantly correlated to mechanical descriptors measured during stair ascent and descent in the 2- and 6-wk ACLR groups (P < 0.05). The Hughston Clinic questionnaire score was correlated to several kinematic variables in the ACL reconstructed knee at 24 wk postoperative, e.g., knee flexion during walking. In the PCL deficient group, the Hughston Clinic questionnaire score was correlated with several kinetic measures, e.g., the peak moment (knee extensors). The Hughston Clinic questionnaire score was not correlated to knee mechanics in the control group. CONCLUSION: The Hughston Clinic questionnaire score has been shown to be valid in this study as it reflects some mechanical descriptors during activities of daily living in the first 6 wk post ACL reconstruction. The questionnaire also provides information on gait modifications by people coping with knee injuries.

A randomized trial comparing povidone-iodine to a chlorhexidine gluconate-impregnated dressing for prevention of central venous catheter infections in neonates.

UNLABELLED: Neonates who require a central venous catheter (CVC) for prolonged vascular access experience high rates of catheter-related bloodstream infection (CRBSI). PURPOSE: A multicenter randomized clinical trial was undertaken to ascertain the efficacy of a novel chlorhexidine-impregnated dressing (Biopatch Antimicrobial Dressing) on the CVC sites of neonates for the prevention of catheter tip colonization, CRBSI, and bloodstream infection (BSI) without a source. Setting. Six level III neonatal intensive care units. Patients Studied. Neonates admitted to study units who would require a CVC for at least 48 hours. METHODS: Eligible infants were randomized before catheter placement to 1 of the 2 catheter site antisepsis regimens: 1) 10% povidone-iodine (PI) skin scrub, or 2) a 70% alcohol scrub followed by placement of a chlorhexidine-impregnated disk over the catheter insertion site. A transparent polyurethane dressing (Bioclusive Transparent Dressing) was used to cover the insertion site in both study groups. Primary study outcomes evaluated were catheter tip colonization, CRBSI, and BSI without an identified source. RESULTS: Seven hundred five neonates were enrolled in the trial, 335 randomized to receive the chlorhexidine dressing and 370 to skin disinfection with PI (controls). Neonates randomized to the antimicrobial dressing group were less likely to have colonized CVC tips than control neonates (15.0% vs 24.0%, relative risk [RR]: 0.6 95% confidence interval [CI]: 0.5-0.9). Rates of CRBSI (3.8% vs 3.2%, RR: 1.2, CI: 0.5-2.7) and BSI without a source (15.2% vs 14.3%, RR: 1.1, CI: 0.8-1.5) did not differ between the 2 groups. Localized contact dermatitis from the antimicrobial dressing, requiring crossover into the PI treatment group, occurred in 15 (15.3%) of 98 exposed neonates weighing

Wingless-type frizzled protein receptor signaling and its putative role in human colon cancer.

We wish to identify new candidate genes involved in the pathogenesis of human colon cancer to better understand the diversity of phenotype presentation that varies from individual to individual. Our working hypothesis is that genetic polymorphism of genes in the Wingless-type (Wnt) frizzled protein receptor pathway is associated with the susceptibility to develop colon cancer. The putative role of the Wnt pathway in sporadic human malignancy of the colon suggests involvement in inherited cancer as well. beta-catenin is the crucial messenger in frizzled receptor signaling, transmitting Wnt-ligand signals such as signals from secreted apoptosis-related proteins to the nucleus. It functions as a genome denunciator by initiating amplification of oncogenes. The net effect of beta-catenin depends on the magnitude of its accumulation in the cytoplasm and, therefore, upon expression profiles of genes in the Wnt pathway. We propose that variations in allelic frequencies of genes involved in the beta-catenin cascade may either promote or impede malignant transformation of the colon. If certain polymorphisms in Wnt signaling through beta-catenin predispose to colon cancer, this might manifest as decreased binding affinity of proteins such as axin or the adenomatous polyposis coli protein to beta-catenin. Association studies are proposed to test the hypothesis, which could serve as an initial step toward understanding the complexity of tumor biology. The clinical rationale in unraveling the genetic susceptibility to cancer lies in identification of a subgroup of individuals who may benefit from beta-catenin targeting agents, which could potentially overcome this genetic instability.

HIV risk behavior and risk-related characteristics of young Russian men who exchange sex for money or valuables from other men.

One of the world's newest HIV epidemics is emerging now in Russia and other countries of Central and Eastern Europe. We report on the HIV risk characteristics of young Russian men who exchange sex for money or valuables, a group that constitutes almost one-fourth of men surveyed recently in gay-identified venues in St. Petersburg. Among 96 MSM who have sex for economic gain, most reported multiple male and female partners, 45% had unprotected anal intercourse with their male partners in the past three months, and many not only received but also gave money or valuables themselves to their male partners. Relative to men who did not give sex for economic gain (n = 326), those who did were younger (n = .0001), less well-educated (p = .0001), and more often unemployed (p = .02). They also were less knowledgeable concerning even basic HIV risk reduction steps (p = .02) and held many misconceptions about safer sex. Men who exchanged sex for economic gain had more male (p = .001) and female partners (p = .01) in the past three months than men who did not, and one-third had been treated for STDs. In the context of Russia's rapid cultural and social changes, economic turmoil, and gay communities not yet experienced in AIDS, HIV prevention programs must be tailored to risk patterns and dynamics different than those found in the gay communities of many western countries.

Predictors of HIV risk behavior among Russian men who have sex with men: an emerging epidemic.

BACKGROUND: Russia is experiencing one of the sharpest increases in HIV incidence in the world. Almost no research has examined patterns of risk behavior among Russian men who have sex with men (MSM). DESIGN AND METHODS: A total of 434 MSM were surveyed in all of St. Petersburg's gay-identified clubs during June 2000. Men completed questionnaires about their sexual practices, AIDS risk knowledge, safer sex attitudes, behavior change intentions, perceived safer sex norms, and fatalism. RESULTS: Most MSM were bisexual; 79% had female partners in their lives and 37% had female partners in the previous 3 months. Sexually transmitted disease treatment was reported by 32% of the men, 23% had sold sex to gain money, and knowledge about critical HIV risk-reduction steps was low. Of all men surveyed, 38% had unprotected anal sex in the previous 3 months, consistent condom use was reported by only 30% of men, and most recent anal intercourse occasions 37% of particpants'. Regression analyses showed that high-risk behavior was predicted by poor safer sex attitudes, weak behavior change intentions, low knowledge about AIDS risk, perceived peer norms that did not support safer sex, and having a boyfriend. CONCLUSION: To avert a widespread epidemic, HIV prevention interventions for Russian MSM are critically needed. Factors predicting risk were consistent with those found among MSM in other countries early in the HIV epidemic. However, unique cultural factors, including frequent bisexual behavior, the 'newness' of openly gay communities in Russia and lack of community experience in dealing with AIDS, require HIV prevention program tailoring.

Effect of treatment on quality of life among men with clinically localized prostate cancer.

BACKGROUND: Quality-of-life outcomes are an important consideration for patients evaluating therapeutic options for localized prostate cancer. OBJECTIVES: The objective of this study was to describe the effect of treatment choice on change in health-related quality of life (HRQOL) among men with clinically localized prostate cancer. RESEARCH DESIGN: This was a prospective observational study. SUBJECTS: The study subjects were 122 men with clinically localized adenocarcinoma of the prostate. Forty-two subjects (34%) underwent radical prostatectomy, 51 (42%) underwent radiation therapy, and 29 (24%) were followed with expectant management. MEASURES: The University of California at Los Angeles Prostate Cancer Quality of Life Inde- and the Medical Outcomes Study Short Form-36 were administered before and 3 and 12 months after initial treatment. The study used an analysis of covariance model adjusted for baseline differences in clinical and demographic factors. RESULTS: Men who underwent radical prostatectomy experienced significant declines in urinary and sexual function and bother that persisted at 12 months after treatment. Men treated with radiation therapy experienced smaller but significant declines in sexual function and a decline in social function. Expectant management patients did not have a significant change in disease-targeted or generic HRQOL domains. Differential rates of change in urinary and sexual function between treatment groups persisted after adjustment for differences in pretreatment clinical and demographic factors. CONCLUSIONS: Men undergoing radical prostatectomy have substantial declines in urinary and sexual function, and men undergoing radiotherapy have declines in sexual function. Men undergoing expectant management have no change in disease-specific or general HRQOL in the first year after treatment.

Factors associated with toilet training in the 1990s.

CONTEXT: Few studies have systematically evaluated the factors influencing toilet training in children with normal development. OBJECTIVES: To determine those child, parent, and environmental factors associated with toilet training completion, focusing on the influence of the child's temperament and development. DESIGN AND SETTING: Cross-sectional descriptive study of normal children, ages 15-42 months, attending 1 of 4 pediatric clinics in Milwaukee in 1995 and 1996. METHODS: Demographics for child, parents, and household were surveyed. Temperament was assessed using the Toddler Temperament Scale and the Behavioral Style Questionnaire. Child development was measured using the Bayley Scales of Infant Development II. MAIN OUTCOME MEASURE: Toilet training status was by parental report and was categorized as not trained, not currently training, in training, or training complete. RESULTS: The study population included 496 children, comprising 219 that had not started training, 70 that were not currently training, 148 that were in training, and 59 that were completely trained. The ages at which 50% of the children were predicted to be toilet trained were 35 and 39 months for girls and boys, respectively. In the multivariate regression model, statistically significant factors best predicting toilet training completion were older age, non-Caucasian race, female gender, and single parenthood. Temperament, development, maternal employment, or use of day care were not statistically significant factors. CONCLUSION: Innate factors such as older age, non-Caucasian race, and female gender are the best predictors of completing toilet training (rather than a child's temperament and developmental stage). Day care and maternal employment appear to be unimportant variables. Parents should not be discouraged, because children are completing toilet training at older ages. Research is needed to discover why single parents are more successful at toilet training.

Correlates of knee laxity change in early rehabilitation after anterior cruciate ligament reconstruction.

Factors other than ligament graft length (knee ROM, knee swelling, initial knee laxity) may need to be accounted for in interpreting changes in knee laxity during rehabilitation following anterior cruciate ligament reconstruction (ACLR) surgery. Twenty-three patients recovering from ACLR surgery (16 M, 7 F, age mean = 30) were tested at 2 and 6 weeks after ACLR with knee laxity measured using th Knee Signature System arthrometer, passive ROM with a standard goniometer and swelling by measuring knee circumference at the mid-patella level using a cloth measuring tape. Spearman correlation coefficients (in parentheses) were calculated using rankings of the change in the injured minus uninjured knee laxity as the dependent variable and the following independent variables: pre-test injured minus uninjured knee laxity (ranked; -0.457; statistically significant two-tailed P < 0.05); change in injured knee maximum extension relative to the uninjured side (ranked; 0.127); change in injured knee maximum flexion relative to the uninjured side (unranked; -0.073); and change in the injured minus uninjured knee girth (unranked; -0.159). These results indicate that consideration should be given to the patient's knee laxity at the start of intervention when using changes in laxity to guide rehabilitation after ACLR.

Bridging the gap between the science and service of HIV prevention: transferring effective research-based HIV prevention interventions to community AIDS service providers.

OBJECTIVES: AIDS service organizations (ASOs) rarely have access to the information needed to implement research-based HIV prevention interventions for their clients. We compared the effectiveness of 3 dissemination strategies for transferring HIV prevention models from the research arena to community providers of HIV prevention services. METHODS: Interviews were conducted with the directors of 74 ASOs to assess current HIV prevention services. ASOs were randomized to programs that provided (1) technical assistance manuals describing how to implement research-based HIV prevention interventions, (2) manuals plus a staff training workshop on how to conduct the implementation, or (3) manuals, the training workshop, and follow-up telephone consultation calls. Follow-up interviews determined whether the intervention model had been adopted. RESULTS: The dissemination package that provided ASOs with implementation manuals, staff training workshops, and follow-up consultation resulted in more frequent adoption and use of the research-based HIV prevention intervention for gay men, women, and other client populations. CONCLUSIONS: Strategies are needed to quickly transfer research-based HIV prevention methods to community providers of HIV prevention services. Active collaboration between researchers and service agencies results in more successful program adoption than distribution of implementation packages alone.

Subsequent pulmonary embolism: risk after a negative helical CT pulmonary angiogram--prospective comparison with scintigraphy.

PURPOSE: To determine whether a helical computed tomographic (CT) scan that is negative for pulmonary embolism (PE) is a sufficiently reliable criterion to safely withhold anticoagulation therapy. MATERIALS AND METHODS: Patients with negative helical CT scans were prospectively compared with patients with negative or low-probability scintigrams. In a 460-bed university hospital and clinic, 1,015 adult patients underwent either scintigraphy or helical CT for possible PE for 25 months. Five hundred forty-eight patients who had negative images and were not receiving anticoagulation therapy were prospectively followed up for 3 months for clinical, new imaging, death certificate, or autopsy evidence of subsequent PE. Ninety-seven patients were lost to follow-up. RESULTS: Subsequent PE was found in two (1.0%) of 198 patients with negative CT scans, none of 188 patients with negative ventilation-perfusion (V-P) scans, and five (3.1%) of 162 patients with low-probability V-P scans (not statistically significant). Patients in the helical CT group were hospitalized more often, had more severe disease, had more substantial PE risk factors, and had a higher death rate. No deaths were attributed to PE in either group. CONCLUSION: The frequency of clinical diagnoses of PE after a negative CT scan was low and similar to that after a negative or low-probability V-P scan. Helical CT is a reliable imaging tool for excluding clinically important PE.

Patterns, correlates, and barriers to medication adherence among persons prescribed new treatments for HIV disease.

New treatments for HIV can improve immune functioning and decrease mortality. However, lapses in adherence may render these complex regimens ineffective. Sixty-three men and 9 women on highly active antiretroviral therapy completed measures of medication adherence, psychological characteristics, and barriers to adherence. HIV viral load, a health outcome measure of virus amount present in blood, was also obtained. The sample was 36% African American and 56% Caucasian, with 35% reporting disability. Nearly one third of patients had missed medication doses in the past 5 days, and 18% had missed doses weekly over the past 3 months. Frequency of missed doses was strongly related to detectable HIV viral loads. Depression, side-effect severity, self-efficacy, and social support distinguished patients with good and poor adherence. Barriers also varied with adherence level. Implications for interventions promoting HIV treatment adherence are discussed.

Underutilization of mammography in older breast cancer survivors.

BACKGROUND: Annual mammography is recommended for all breast cancer survivors. OBJECTIVES: To elucidate mammography use among older survivors of breast cancer and to explore determinants of such use. RESEARCH DESIGN: Retrospective cohort study using data from the Surveillance, Epidemiology, and End Results (SEER) registry linked to Medicare claims. SUBJECTS: A cohort of 3885 breast cancer survivors aged > or =65 years diagnosed with early-stage breast cancer in the United States in 1991. MEASURES: Medicare mammogram claims during the 2-year period following initial breast cancer treatment. RESULTS: Overall, 62% of the cohort underwent annual mammography, 23% underwent mammography in 1 of 2 years, and 15% had no mammography claim in the 2 years evaluated. Twenty-two percent of the women who underwent breast-conserving surgery (BCS) without radiotherapy had no mammogram in the 2-year period evaluated, compared with 17% of those who underwent mastectomy and 4% of those who underwent BCS with radiotherapy. In multivariate analyses controlling for age, cancer stage, and other patient factors, the use of annual mammography was significantly lower among women treated with mastectomy or BCS without radiotherapy than among women treated with BCS with radiotherapy. CONCLUSIONS: Mammography is underused in the follow-up care of older breast cancer survivors. Underuse is of particular concern in women treated with BCS without radiotherapy because of the high risk of local disease recurrence. It is unknown whether poorer follow-up care contributes to the previously described lower rate of long-term survival among women who received this therapy.