338 research outputs found

    A longitudinal study of adult-onset asthma incidence among HMO members

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    BACKGROUND: HMO databases offer an opportunity for community based epidemiologic studies of asthma incidence, etiology and treatment. The incidence of asthma in HMO populations and the utility of HMO data, including use of computerized algorithms and manual review of medical charts for determining etiologic factors has not been fully explored. METHODS: We identified adult-onset asthma, using computerized record searches in a New England HMO. Monthly, our software applied exclusion and inclusion criteria to identify an "at-risk" population and "potential cases". Electronic and paper medical records from the past year were then reviewed for each potential case. Persons with other respiratory diseases or insignificant treatment for asthma were excluded. Confirmed adult-onset asthma (AOA) cases were defined as those potential cases with either new-onset asthma or reactivated mild intermittent asthma that had been quiescent for at least one year. We validated the methods by reviewing charts of selected subjects rejected by the algorithm. RESULTS: The algorithm was 93 to 99.3% sensitive and 99.6% specific. Sixty-three percent (n = 469) of potential cases were confirmed as AOA. Two thirds of confirmed cases were women with an average age of 34.8 (SD 11.8), and 45% had no evidence of previous asthma diagnosis. The annualized monthly rate of AOA ranged from 4.1 to 11.4 per 1000 at-risk members. Physicians most commonly attribute asthma to infection (59%) and allergy (14%). New-onset cases were more likely attributed to infection, while reactivated cases were more associated with allergies. Medical charts included a discussion of work exposures in relation to asthma in only 32 (7%) cases. Twenty-three of these (72%) indicated there was an association between asthma and workplace exposures for an overall rate of work-related asthma of 4.9%. CONCLUSION: Computerized HMO records can be successfully used to identify AOA. Manual review of these records is important to confirm case status and is useful in evaluation of provider consideration of etiologies. We demonstrated that clinicians attribute most AOA to infection and tend to ignore the contribution of environmental and occupational exposures

    Identification of novel subgroup a variants with enhanced receptor binding and replicative capacity in primary isolates of anaemogenic strains of feline leukaemia virus

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    <b>BACKGROUND:</b> The development of anaemia in feline leukaemia virus (FeLV)-infected cats is associated with the emergence of a novel viral subgroup, FeLV-C. FeLV-C arises from the subgroup that is transmitted, FeLV-A, through alterations in the amino acid sequence of the receptor binding domain (RBD) of the envelope glycoprotein that result in a shift in the receptor usage and the cell tropism of the virus. The factors that influence the transition from subgroup A to subgroup C remain unclear, one possibility is that a selective pressure in the host drives the acquisition of mutations in the RBD, creating A/C intermediates with enhanced abilities to interact with the FeLV-C receptor, FLVCR. In order to understand further the emergence of FeLV-C in the infected cat, we examined primary isolates of FeLV-C for evidence of FeLV-A variants that bore mutations consistent with a gradual evolution from FeLV-A to FeLV-C.<p></p> <b>RESULTS:</b> Within each isolate of FeLV-C, we identified variants that were ostensibly subgroup A by nucleic acid sequence comparisons, but which bore mutations in the RBD. One such mutation, N91D, was present in multiple isolates and when engineered into a molecular clone of the prototypic FeLV-A (Glasgow-1), enhanced replication was noted in feline cells. Expression of the N91D Env on murine leukaemia virus (MLV) pseudotypes enhanced viral entry mediated by the FeLV-A receptor THTR1 while soluble FeLV-A Env bearing the N91D mutation bound more efficiently to mouse or guinea pig cells bearing the FeLV-A and -C receptors. Long-term in vitro culture of variants bearing the N91D substitution in the presence of anti-FeLV gp70 antibodies did not result in the emergence of FeLV-C variants, suggesting that additional selective pressures in the infected cat may drive the subsequent evolution from subgroup A to subgroup C.<p></p> <b>CONCLUSIONS:</b> Our data support a model in which variants of FeLV-A, bearing subtle differences in the RBD of Env, may be predisposed towards enhanced replication in vivo and subsequent conversion to FeLV-C. The selection pressures in vivo that drive the emergence of FeLV-C in a proportion of infected cats remain to be established

    Oral Bisphosphonates and Risk of Atrial Fibrillation and Flutter in Women: A Self-Controlled Case-Series Safety Analysis

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    Background: A recent trial unexpectedly reported that atrial fibrillation, when defined as serious, occurred more often in participants randomized to an annual infusion of the relatively new parenteral bisphosphonate, zoledronic acid, than among those given placebo, but had limited power. Two subsequent population-based case-control studies of patients receiving a more established oral bisphosphonate, alendronic acid, reported conflicting results, possibly due to uncontrolled confounding factors.Methodology/Principal Findings: We used the United Kingdom General Practice Research Database to assess the risk of atrial fibrillation and flutter in women exposed to the oral bisphosphonates, alendronic acid and risedronate sodium. The self-controlled case-series method was used to minimise the potential for confounding. The age-adjusted incidence rate ratio for atrial fibrillation or flutter in individuals during their exposure to these oral bisphosphonates (n = 2195) was 1.07 (95% CI 0.94 - 1.21). The age-adjusted incidence rate ratio for alendronic acid (n = 1489) and risedronate sodium (n = 649) exposed individuals were 1.09 (95% CI 0.93 - 1.26) and 0.99 (95% CI 0.78 - 1.26) respectively. In post-hoc analyses, an increased risk of incident atrial fibrillation or flutter was detected for patients during their first few months of alendronic acid therapy.Conclusions/Significance: We found no robust evidence of an overall long-term increased risk of atrial fibrillation or flutter associated with continued exposure to the oral bisphosphonates, alendronic acid and risedronate sodium. A possible signal for an increase in risk during the first few months of therapy with alendronic acid needs to be re-assessed in additional studies

    Patient characteristics associated with differences in patients' evaluation of their general practitioner

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    <p>Abstract</p> <p>Background</p> <p>Knowledge of the extent to which patient characteristics are systematically associated with variation in patient evaluations will enable us to adjust for differences between practice populations and thereby compare GPs. Whether this is appropriate depends on the purpose for which the patient evaluation was conducted. Associations between evaluations and patient characteristics may reflect gaps in the quality of care or may be due to inherent characteristics of the patients. This study aimed to determine such associations in a setting with a comprehensive list system and gate-keeping.</p> <p>Methods</p> <p>A nationwide Danish patient evaluation survey among voluntarily participating GPs using the EUROPEP questionnaire, which produced 28,260 patient evaluations (response rate 77.3%) of 365 GPs. In our analyses we compared the prevalence of positive evaluations in groups of patients.</p> <p>Results</p> <p>We found a positive GP assessment to be strongly associated with increasing patient age and increasing frequency of attendance. Patients reporting a chronic condition were more positive, whereas a low self-rated health was strongly associated with less positive scores also after adjustment. The association between patient gender and assessment was weak and inconsistent and depended on the focus. We found no association either with the patients' educational level or with the duration of listing with the GP even after adjusting for patient characteristics.</p> <p>Conclusion</p> <p>Adjustment for patient differences may produce a more fair comparison between GPs, but may also blur the assessment of GPs' ability to meet the needs of the populations actually served. On the other hand, adjusted results will enable us to describe the significance of specific patient characteristics to patients' experience of care.</p

    Asthma self-assessment in a Medicaid population

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    <p>Abstract</p> <p>Background</p> <p>Self-assessment of symptoms by patients with chronic conditions is an important element of disease management. A recent study in a commercially-insured population found that patients who received automated telephone calls for asthma self-assessment felt they benefitted from the calls. Few studies have evaluated the effectiveness of disease self-assessment in Medicaid populations. The goals of this study were to: (1) assess the feasibility of asthma self-assessment in a population predominantly insured by Medicaid, (2) study whether adding a gift card incentive increased completion of the self-assessment survey, and (3) evaluate how the self-assessment affected processes and outcomes of care.</p> <p>Methods</p> <p>We studied adults and children aged 4 years and older who were insured by a Medicaid-focused managed care organization (MCO) in a pre- and post-intervention study. During the pre-incentive period, patients with computerized utilization data that met specific criteria for problematic asthma control were mailed the Asthma Control Test (ACT), a self-assessment survey, and asked to return it to the MCO. During the intervention period, patients were offered a $20 gift card for returning the completed ACT to the MCO. To evaluate clinical outcomes, we used computerized claims data to assess the number of hospitalization visits and emergency department visits experienced in the 3 months after receiving the ACT. To evaluate whether the self-management intervention improved processes of care, we conducted telephone interviews with patients who returned or did not return the ACT by mail.</p> <p>Results</p> <p>During the pre-incentive period, 1183 patients were identified as having problems with asthma control; 25 (2.0%) of these returned the ACT to the MCO. In contrast, during the incentive period, 1612 patients were identified as having problems with asthma control and 87 (5.4%) of these returned the ACT to the MCO (p < 0.0001). Of all 95 ACTs that were returned, 87% had a score of 19 or less, which suggested poor asthma control.</p> <p>During the 3 months after they received the ACT, patients who completed it had similar numbers of outpatient visits, emergency department visits, and hospitalizations for asthma as patients who did not complete the ACT. We completed interviews with 95 patients, including 28 who had completed the ACT and 67 who had not. Based on an ACT administered at the time of the interview, patients who had previously returned the ACT to the MCO had asthma control similar to those who had not (mean scores of 14.2 vs. 14.6, p = 0.70). Patients had similar rates of contacting their providers within the past 2 months whether they had completed the mailed ACT or not (71% vs. 76%, p = 0.57).</p> <p>Conclusion</p> <p>Mailing asthma self-assessment surveys to patients with poorly controlled asthma was not associated with better asthma-associated outcomes or processes of care in the Medicaid population studied. Adding a gift card incentive did not meaningfully increase response rates. Asthma disease management programs for Medicaid populations will most likely need to involve alternative strategies for engaging patients and their providers in managing their conditions.</p

    Risk factors for acquisition of hepatitis C virus infection: a case series and potential implications for disease surveillance

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    BACKGROUND: Transmission of hepatitis C vims (HCV) is strongly associated with use of contaminated blood products and injection drugs. Other "non-parental" modes of transmission including sexual activity have been increasingly recognized. We examined risk factors for acquiring HCV in patients who were referred to two tertiary care centers and enrolled in an antiviral therapy protocol. METHODS: Interviews of 148 patients were conducted apart from their physician evaluation using a structured questionnaire covering demographics and risk factors for HCV acquisition. RESULTS: Risk factors (blood products, injection/intranasal drugs, razor blades/ toothbrushes, body/ear piercing, occupational exposure, sexual activity) were identified in 141 (95.3%) of participants; 23 (15.5%) had one (most frequently blood or drug exposure), 41 (27.7%) had two, and 84 (53.4%) had more than two risk factors. No patient reported sexual activity as a sole risk factor. Body piercing accounted for a high number of exposures in women. Men were more likely to have exposure to street drugs but less exposure to blood products than women. Blood product exposure was less common in younger than older HCV patients. CONCLUSION: One and often multiple risk factors could be identified in nearly all HCV-infected patients seen in a referral practice. None named sexual transmission as the sole risk factor. The development of a more complete profile of factors contributing to transmission of HCV infection may assist in clinical and preventive efforts. The recognition of the potential presence of multiple risk factors may have important implications in the approach to HCV surveillance, and particularly the use of hierarchical algorithms in the study of risk factors

    Distinguishing patterns in the dynamics of long-term medication use by Markov analysis: beyond persistence

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    <p>Abstract</p> <p>Background</p> <p>In order to accurately distinguish gaps of varying length in drug treatment for chronic conditions from discontinuation without resuming therapy, short-term observation does not suffice. Thus, the use of inhalation corticosteroids (ICS) in the long-term, during a ten-year period is investigated. To describe medication use as a continuum, taking into account the timeliness and consistency of refilling, a Markov model is proposed.</p> <p>Methods</p> <p>Patients, that filled at least one prescription in 1993, were selected from the PHARMO medical record linkage system (RLS) containing >95% prescription dispensings per patient originating from community pharmacy records of 6 medium-sized cities in the Netherlands.</p> <p>The probabilities of continuous use, the refilling of at least one ICS prescription in each year of follow-up, and medication free periods were assessed by Markov analysis. Stratified analysis according to new use was performed.</p> <p>Results</p> <p>The transition probabilities of the refilling of at least one ICS prescription in the subsequent year of follow-up, were assessed for each year of follow-up and for the total study period.</p> <p>The change of transition probabilities in time was evaluated, e.g. the probability of continuing ICS use of starters in the first two years (51%) of follow-up increased to more than 70% in the following years. The probabilities of different patterns of medication use were assessed: continuous use (7.7%), cumulative medication gaps (1–8 years 69.1%) and discontinuing (23.2%) during ten-year follow-up for new users. New users had lower probability of continuous use (7.7%) and more variability in ICS refill patterns than previous users (56%).</p> <p>Conclusion</p> <p>In addition to well-established methods in epidemiology to ascertain compliance and persistence, a Markov model could be useful to further specify the variety of possible patterns of medication use within the continuum of adherence. This Markov model describes variation in behaviour and patterns of ICS use and could also be useful to investigate continuous use of other drugs applied in chronic diseases.</p

    Aberrant overexpression of an epithelial marker, 14-3-3σ, in a subset of hematological malignancies

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    <p>Abstract</p> <p>Background</p> <p>14-3-3σ is a p53-mediated cell-cycle inhibitor in epithelial cells. The expression of 14-3-3σ is frequently altered in cancers of epithelial origin associated with altered DNA methylation. Since its involvement in a non-epithelial tumor is unknown, we examined 14-3-3σ expression in patients with haematological malignancies.</p> <p>Methods</p> <p>We analyzed 41 hematopoietic cell lines and 129 patients with a variety of hematological malignancies for 14-3-3σ expression with real-time RT-PCR. We also examined protein levels by Western blot analysis and DNA methylation status of the 14-3-3σ gene by methylation-specific PCR analysis of bisulfite-treated DNA. In addition, mutations of p53 gene were identified by RT-PCR-SSCP analysis and the expression levels of 14-3-3σ were compared with those of other cell-cycle inhibitor genes, CDKN2A and ARF.</p> <p>Results</p> <p>The expression levels of 14-3-3σ mRNA in almost all cell lines were low and comparable to those in normal hematopoietic cells except for 2 B-cell lines. On the contrary, 14-3-3σ mRNA was aberrantly overexpressed frequently in mature lymphoid malignancies (30 of 93, 32.3%) and rarely in acute leukemia (3 of 35, 8.6%). 14-3-3σ protein was readily detectable and roughly reflected the mRNA level. In contrast to epithelial tumors, methylation status of the 14-3-3σ gene was not associated with expression in hematological malignancies. Mutations of p53 were identified in 12 patients and associated with lower expression of 14-3-3σ. The expression levels of 14-3-3σ, CDKN2A and ARF were not correlated with but rather reciprocal to one another, suggesting that simultaneous overexpression of any two of them is incompatible with tumor growth.</p> <p>Conclusion</p> <p>14-3-3σ, an epithelial cell marker, was overexpressed significantly in a subset of mature lymphoid malignancies. This is the first report of aberrant 14-3-3σ expression in non-epithelial tumors <it>in vivo</it>. Since the significance of 14-3-3σ overexpression is unknown even in epithelial tumors such as pancreatic cancers, further analysis of regulation and function of the 14-3-3σ gene in non-epithelial as well as epithelial tumors is warranted.</p
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