The Imperfective Past

The objective of our study was to investigate whether use of antipsychotics is associated with hip/femur fractures and whether pharmacological differences between antipsychotics are related to the occurrence of fractures.A case-control study was conducted, in which cases were defined as patients with a hip/femur fracture. Each patient was matched to one control patient. The association between use of antipsychotics and the occurrence of hip/femur fractures was evaluated using conditional logistic regression.The study included 44,500 patients from 683 general practices from different geographical areas in the UK, registered within the General Practice Research Database (GPRD). Exposure to antipsychotics was categorized as “no use”, “current use” and “prior use”.Both current and prior use of antipsychotics were associated with an approximately two-fold increased risk of fractures. After adjustment for possible confounders, a small significant effect remained (Odds Ratios (OR) of 1.3). We did not find an association between dose of antipsychotics, or between the degree of blockade of the alpha-1 adrenoceptor or histamine-1 receptor and risk of fractures. The total number of days of antipsychotic use was significantly associated with an increased risk of hip/femur fractures.We conclude that there is a small increased risk of hip/femur fractures associated with the use of antipsychotics. This risk increases with long-term use

The proxy problem anatomized: child-parent disagreement in health related quality of life reports of chronically ill adolescents

<p>Abstract</p> <p>Background</p> <p>Discrepancy between self-reports and parent-proxy reports of adolescent health-related quality of life (HRQoL) has been repeatedly acknowledged in the literature as the proxy problem. However, little is known about the extent and direction of this discrepancy. The purpose of this study is to explore to what extent and in what direction HRQoL self-reports of adolescents with chronic conditions and those of their parents differ.</p> <p>Methods</p> <p>A cross-sectional survey was conducted among adolescents suffering from chronic conditions and their parents. Socio-demographic and disease-related characteristics were collected and information about consequences of the chronic condition was assessed. HRQoL was measured with KIDSCREEN-10 and DISABKIDS condition generic measure (DCGM-10). Agreement was analysed through defining a threshold of agreement based on half of the standard deviation of the HRQoL score with the highest variance. Agreement occurred if the difference between adolescent and parent scores was less than or equal to half of the standard deviation. Intra-class correlation coefficients and Bland-Altman plots were also computed. The characteristics associated with direction of disagreement were statistically tested with one-way ANOVA and Chi-square tests.</p> <p>Results</p> <p>584 paired HRQoL scores were obtained. Ratings from both adolescents and parents were high, compared to European norm data. Differences between adolescents and parents were statistically significant, yet relatively small. Disagreement existed in both directions: in 24.5% (KIDSCREEN-10) and 16.8% (DCGM-10) of the cases adolescents rated their HRQoL lower than did their parent, while in 32.2% (KIDSCREEN-10) and 31.7% (DCGM-10) of the cases the opposite was true. Adolescent's age, educational level and type of education, parent's educational level, number of hospital admissions and several other disease-related factors influenced direction of disagreement.</p> <p>Conclusions</p> <p>In a reasonable proportion of cases the adolescent and parent agreed on the adolescent's HRQoL (43-51% of the cases) and most disagreement tended to be minor. Thus, the proxy problem may be smaller than presented in the literature and its extent may differ per population. As adolescents are expected to become partners in their own health care, it is recommended to focus on adolescents' own perceptions of HRQoL.</p

Evaluation of biases present in the cohort multiple randomised controlled trial design: a simulation study

Background The cohort multiple randomised controlled trial (cmRCT) design provides an opportunity to incorporate the benefits of randomisation within clinical practice; thus reducing costs, integrating electronic healthcare records, and improving external validity. This study aims to address a key concern of the cmRCT design: refusal to treatment is only present in the intervention arm, and this may lead to bias and reduce statistical power. Methods We used simulation studies to assess the effect of this refusal, both random and related to event risk, on bias of the effect estimator and statistical power. A series of simulations were undertaken that represent a cmRCT trial with time-to-event endpoint. Intention-to-treat (ITT), per protocol (PP), and instrumental variable (IV) analysis methods, two stage predictor substitution and two stage residual inclusion, were compared for various refusal scenarios. Results We found the IV methods provide a less biased estimator for the causal effect when refusal is present in the intervention arm, with the two stage residual inclusion method performing best with regards to minimum bias and sufficient power. We demonstrate that sample sizes should be adapted based on expected and actual refusal rates in order to be sufficiently powered for IV analysis. Conclusion We recommend running both an IV and ITT analyses in an individually randomised cmRCT as it is expected that the effect size of interest, or the effect we would observe in clinical practice, would lie somewhere between that estimated with ITT and IV analyses. The optimum (in terms of bias and power) instrumental variable method was the two stage residual inclusion method. We recommend using adaptive power calculations, updating them as refusal rates are collected in the trial recruitment phase in order to be sufficiently powered for IV analysis

Patient perceived needs and experiences of person-centered care in patients with inflammatory arthritis

BACKGROUND: Health care is shifting toward a person-centered care (PCC) approach. For implementation of PCC, there may be a special role for nurse practitioners (NPs). PURPOSE: The aim of this study was to explore the patient-perceived levels of and needs for of PCC in inflammatory arthritis patients who visited the NP at the outpatient clinic of an academic hospital in the Netherlands. METHODS: A cross-sectional study was performed. Disease characteristics were inventoried from the patient records. Patients filled out the PCCoc/rheum instrument, an instrument to measure patient perceived PCC, and a questionnaire based on the 14 life areas of the Self-Management Web, extended with areas including pain, fatigue, and night's rest. Participants were asked which life areas caused problems, and whether these problems were discussed. Mean values were calculated for normally distributed data and medians for nonnormally distributed data. RESULTS: Most of the patients had well-controlled disease (86.1%). The mean score of the PCCoc/rheum was 55.3 (SD 8.1). Patients experienced most problems in life areas fatigue (37.3%) and pain (35.3%), these were also the life areas that were most often addressed at consultation. The life areas that gave problems and that were least addressed during consultation were intimate relationships & sexuality (66.7%) and household chores (58.8%). CONCLUSIONS: Despite an overall high level of patient perceived PCC delivered by NPs, patient with low disease activity frequently reported problems in life areas not addressed at consultation. IMPLICATIONS FOR PRACTICE: Implementation of the Self-Management Web and changing the focus of NP consultations may help to improve accommodating individual patient needs

The development and psychometric validation of the self-efficacy and performance in self-management support (SEPSS) Instrument

__Aim:__ To develop and psychometrically test the self-efficacy and performance in self-management support (SEPSS) instrument. __Background:__ Facilitating persons with a chronic condition to take an active role in the management of their condition, implicates that nurses acquire new competencies. An instrument that can validly and reliably measure nurses' performance and their perceived capacity to perform self-management support is needed to evaluate current practice and training in self-management support. __Design:__ Instrument development and psychometric testing of the content and construct validity, factor structure and reliability. __Methods:__ A literature review and expert consultation (N = 17) identified the content. The items were structured according to the Five-A's model and an overarching category of 'overall' competencies. The initial instrument was tested in a sample of 472 nurses and 51 nursing students from Belgium and the Netherlands, between June 2014-January 2015. __Results:__ Confirmatory factor analyses revealed satisfactory fit indices for the six-factor structure. Discriminating power was demonstrated for subgroups. The overall internal consistency (Cronbach's alpha) was high both for the self-efficacy and the performance items. The test-retest intra-class correlation coefficients were good. __Conclusion:__ The SEPSS instrument is a 36-item, Likert-scaled self-reporting instrument with good content and construct validity, and good internal consistency reliability and good test-retest reliability. Therefore, it is a promising instrument to measure self-efficacy and performance with regard to self-management support

О. Олесь

О. Олесь (справж. прізв. - Олександр Іванович Кандиба; 1878-1944) - український поет

The optical system of the H.E.S.S. imaging atmospheric Cherenkov telescopes, Part II: mirror alignment and point spread function

Mirror facets of the H.E.S.S. imaging atmospheric Cherenkov telescopes are aligned using stars imaged onto the closed lid of the PMT camera, viewed by a CCD camera. The alignment procedure works reliably and includes the automatic analysis of CCD images and control of the facet alignment actuators. On-axis, 80% of the reflected light is contained in a circle of less than 1 mrad diameter. The spot widens with increasing angle to the telescope axis. In accordance with simulations, the spot size has roughly doubled at an angle of 1.4 degr. from the axis. The expected variation of spot size with elevation due to deformations of the support structure is visible, but is completely non-critical over the usual working range. Overall, the optical quality of the telescope exceeds the specifications.Comment: 23 pages, 13 figure

Potential application of item-response theory to interpretation of medical codes in electronic patient records

Background: electronic patient records are generally coded using extensive sets of codes but the significance of the utilisation of individual codes may be unclear. Item response theory (IRT) models are used to characterise the psychometric properties of items included in tests and questionnaires. This study asked whether the properties of medical codes in electronic patient records may be characterised through the application of item response theory models.Methods: data were provided by a cohort of 47,845 participants from 414 family practices in the UK General Practice Research Database (GPRD) with a first stroke between 1997 and 2006. Each eligible stroke code, out of a set of 202 OXMIS and Read codes, was coded as either recorded or not recorded for each participant. A two parameter IRT model was fitted using marginal maximum likelihood estimation. Estimated parameters from the model were considered to characterise each code with respect to the latent trait of stroke diagnosis. The location parameter is referred to as a calibration parameter, while the slope parameter is referred to as a discrimination parameter.Results: there were 79,874 stroke code occurrences available for analysis. Utilisation of codes varied between family practices with intraclass correlation coefficients of up to 0.25 for the most frequently used codes. IRT analyses were restricted to 110 Read codes. Calibration and discrimination parameters were estimated for 77 (70%) codes that were endorsed for 1,942 stroke patients. Parameters were not estimated for the remaining more frequently used codes. Discrimination parameter values ranged from 0.67 to 2.78, while calibration parameters values ranged from 4.47 to 11.58. The two parameter model gave a better fit to the data than either the one- or three-parameter models. However, high chi-square values for about a fifth of the stroke codes were suggestive of poor item fit.Conclusion: the application of item response theory models to coded electronic patient records might potentially contribute to identifying medical codes that offer poor discrimination or low calibration. This might indicate the need for improved coding sets or a requirement for improved clinical coding practice. However, in this study estimates were only obtained for a small proportion of participants and there was some evidence of poor model fit. There was also evidence of variation in the utilisation of codes between family practices raising the possibility that, in practice, properties of codes may vary for different coder