Mean Number Of Measurements Research Articles

Effects of salt intake reduction by urinary sodium to potassium ratio self-monitoring method.

Effective and feasible educational methods are needed to control salt intake. We performed a single-center, non-randomized controlled study to investigate the effectiveness and feasibility of self-monitoring using a urinary sodium/potassium (Na/K) ratio-measuring device in patients with difficulty in reducing salt intake. This study included 160 patients with hypertension, chronic kidney disease, or heart disease who were followed up in the outpatient clinic of the Dokkyo Medical University Nikko Medical Center. Urinary Na/K ratio measuring Na/K ratio meter were loaned for 2-6 weeks to the treatment (T) group (n = 80) and not to the patients in the control (C) group (n = 80). In the T group, patients were instructed to measure the urinary Na/K ratio at least three times a day and maintain a Na/K ratio below 2.0. Salt reduction education and home blood pressure measurement guidance continued in both groups. The mean device loan period in the T group was 25.1 days, the mean number of measurements was 3.0 times/day, and the proportion of patients achieving three measurements per day was 48.8% (39/80). Self-monitoring using the urinary Na/K ratio meter successfully reduced salt intake by -1.9 g/day at the second visit (p < 0.001) in the T group. In contrast, no change was observed over time in the C group. Self-monitoring using the urinary Na/K ratio meter successfully reduced salt intake in patients with difficulty reducing salt intake.

Impact of the COVID-19 pandemic on routine surveillance for adults with chronic hepatitis B virus (HBV) infection in the UK.

To determine the impact of the COVID-19 pandemic on the population with chronic Hepatitis B virus (HBV) infection under hospital follow-up in the UK, we quantified the coverage and frequency of measurements of biomarkers used for routine surveillance (alanine transferase [ALT] and HBV viral load). We used anonymized electronic health record data from the National Institute for Health Research (NIHR) Health Informatics Collaborative (HIC) pipeline representing five UK National Health Service (NHS) Trusts. We report significant reductions in surveillance of both biomarkers during the pandemic compared to pre-COVID-19 years, both in terms of the proportion of patients who had ≥1 measurement annually, and the mean number of measurements per patient. These results demonstrate the real-time utility of HIC data in monitoring health-care provision, and support interventions to provide catch-up services to minimise the impact of the pandemic. Further investigation is required to determine whether these disruptions will be associated with increased rates of adverse chronic HBV outcomes.

Therapeutic Drug Monitoring (TDM) Implementation in Public Hospitals in Greece in 2003 and 2021: A Comparative Analysis of TDM Evolution over the Years.

Therapeutic drug monitoring (TDM) is the clinical practice of measuring drug concentrations. TDM can be used to determine treatment efficacy and to prevent the occurrence or reduce the risk of drug-induced side effects, being, thus, a tool of personalized medicine. Drugs for which TDM is applied should have a narrow therapeutic range and exhibit both significant pharmacokinetic variability and a predefined target concentration range. The aim of our study was to assess the current status of TDM in Greek public hospitals and estimate its progress over the last 20 years. All Greek public hospitals were contacted to provide data and details on the clinical uptake of TDM in Greece for the years 2003 and 2021 through a structured questionnaire. Data from 113 out of 132 Greek hospitals were collected in 2003, whereas for 2021, we have collected data from 98 out of 122 hospitals. Among these, in 2003 and 2021, 64 and 51 hospitals, respectively, performed TDM. Antiepileptics and antibiotics were the most common drug categories monitored in both years. The total number of drug measurement assays decreased from 2003 to 2021 (153,313 ± 7794 vs. 90,065 ± 5698; p = 0.043). In direct comparisons between hospitals where TDM was performed both in 2003 and 2021 (n = 35), the mean number of measurements was found to decrease for most drugs, including carbamazepine (198.8 ± 46.6 vs. 46.6 ± 10.1, p < 0.001), phenytoin (253.6 ± 59 vs. 120 ± 34.3; p = 0.001), amikacin (147.3 ± 65.2 vs. 91.1 ± 71.4; p = 0.033), digoxin (783.2 ± 226.70 vs. 165.9 ± 28.9; p < 0.001), and theophylline (71.5 ± 28.7 vs. 11.9 ± 6.4; p = 0.004). Only for vancomycin, a significant increase in measurements was recorded (206.1 ± 96.1 vs. 789.1 ± 282.8; p = 0.012). In conclusion, our findings show that TDM clinical implementation is losing ground in Greek hospitals. Efforts and initiatives to reverse this trend are urgently needed.

Impact of the COVID-19 pandemic on routine surveillance for adults with chronic hepatitis B virus (HBV) infection in the UK

Background: To determine the impact of the COVID-19 pandemic on the population with chronic Hepatitis B virus (HBV) infection under hospital follow-up in the UK, we quantified the coverage and frequency of measurements of biomarkers used for routine surveillance (alanine transferase [ALT] and HBV viral load). Methods: We used anonymized electronic health record data from the National Institute for Health Research (NIHR) Health Informatics Collaborative (HIC) pipeline representing five UK National Health Service (NHS) Trusts. Results: We report significant reductions in surveillance of both biomarkers during the pandemic compared to pre-COVID-19 years, both in terms of the proportion of patients who had ≥1 measurement annually, and the mean number of measurements per patient. Conclusions: These results demonstrate the real-time utility of HIC data in monitoring health-care provision, and support interventions to provide catch-up services to minimise the impact of the pandemic. Further investigation is required to determine whether these disruptions will be associated with increased rates of adverse chronic HBV outcomes.

Relationships between lung function decline and skeletal muscle and fat mass changes: a longitudinal study in healthy individuals.

BackgroundThe associations between long‐term changes in body mass composition and decline in lung function in healthy adults are unknown.MethodsUsing a well‐defined health check‐up database, we first assessed individual longitudinal changes in muscle mass (MM) and fat mass (FM) measured via bioelectrical impedance analyses. Then we classified the enrolled individuals into five body composition groups according to their MM index (MMI) [MM (kg)/height (m)2] or FM index (FMI) [FM (kg)/height (m)2] change rate quartiles. Linear mixed models adjusted for age, smoking status, height, and body mass index were used to analyse the rate of forced expiratory volume in 1 s (FEV1) decline and body composition groups.ResultsA total of 15 476 middle‐aged individuals (6088 women [mean age ± standard deviation: 50.74 ± 7.44] and 9388 men [mean age ± standard deviation: 49.36 ± 6.99]) were enrolled. The mean number of measurements was 6.96 (interquartile range [IQR]: 5–9) over an average follow‐up period of 8.95 years (IQR: 6.73–11.10). Decrease in MMI was significantly associated with accelerated FEV1 decline in men only (P = 1.7 × 10−9), while increase in FMI was significantly associated with accelerated FEV1 decline in both women and men (P = 7.9 × 10−10 and P < 2.0 × 10−16 respectively). Linear mixed model analyses indicated that annual increase of 0.1 kg/m2 in MMI was related to accelerated FEV1 decline by 30.79 mL/year (95% confidence interval [CI]: 26.10 to 35.48 mL/year) in men. Annual increase of 0.1 kg/m2 in FMI was related to accelerated FEV1 decline by 59.65 mL/year in men (95% CI: 56.84 to 62.28 mL/year) and by 22.84 mL/year in women (95% CI: 18.95 to 26.74 mL/year). In body composition analysis, we found increase in MMI was significantly associated with attenuated FEV1 decline in men only (P = 1.7 × 10−9), while increase in FMI was significantly associated with accelerated FEV1 decline in both women and men (P = 7.9 × 10−10 and P < 2.0 × 10−16 respectively). Individuals characterized with gain MM combined with loss of FM were associated with the most favourable outcome (i.e. the smallest rate of decline in FEV1) in both women and men. In men, loss of FM over time is more closely related with attenuated FEV1 decline than change in MM (gain or loss).ConclusionsChange in body composition over time can be used to identify healthy middle‐aged individuals at high risk for rapid FEV1 decline.

Randomly repeated measurements on quantum systems: correlations and topological invariants of the quantum evolution

Randomly repeated measurements during the evolution of a closed quantum system create a sequence of probabilities for the first detection of a certain quantum state. The related discrete monitored evolution for the return of the quantum system to its initial state is investigated. We found that the mean number of measurements (MNM) until the first detection is an integer, namely the dimensionality of the accessible Hilbert space. Moreover, the mean first detected return (FDR) time is equal to the average time step between successive measurements times the MNM. Thus, the mean FDR time scales linearly with the dimensionality of the accessible Hilbert space. The main goal of this work is to explain the quantization of the mean return time in terms of a quantized Berry phase.

Frequency of Blood Pressure and Estimated Glomerular Filtration Rate Testing in Type 2 Diabetes Mellitus: A Retrospective Study with 43,509 Patients.

The goal of this study was to analyze the frequency of blood pressure (BP) and estimated glomerular filtration rate (eGFR) testing in type 2 diabetes mellitus (T2DM) patients followed in general and diabetological practices in Germany. The study included individuals who had at least two concultations due to T2DM diagnosis (ICD-10: E11) between January and December 2016. Patients were followed in 557 general and diabetological practices. The primary outcome was the frequency of BP and eGFR testing in T2DM patients in 2016. The association between several demographic and clinical variables and the odds of receiving≥2 BP and≥1 eGFR tests in the year 2016 was analyzed using multivariate logistic regression models. A total of 43,509 individuals were available for analysis. The mean age of the population was 68.6 years (SD=12.4 years). The mean number of measurements was 2.9 (SD=3.5) for BP and 0.4 (SD=1.1) for eGFR. 52.3% of patients were tested at least twice for BP and 15.3% of them at least once for eGFR in 2016. Older patients, individuals followed in diabetological practices, people receiving antihyperglycemic medications, and those affected by chronic conditions (i. e. hypertension, renal complications, or neuropathy) displayed higher odds of receiving≥2 BP and≥1 eGFR tests, whereas patients with a diabetes duration of>1 year displayed lower odds. The frequency of BP and eGFR testing was low in T2DM patients in Germany in 2016. Several demographic and clinical variables were associated with this frequency.

Longitudinal Blood Pressure Changes and Kidney Function Decline in Persons Without Chronic Kidney Disease: Findings From the MESA Study.

While changes in blood pressure (BP) are independently associated with cardiovascular events, less is known about the association between changes in BP and subsequent changes in renal function in adults with an estimated glomerular filtration rate (eGFR) of >60 ml/min/1.73 m2. The present study included 3,920 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) study who had ≥2 BP measurements during the first 5 years of MESA and had eGFR measurements at both year 5 and 10. Change in BP was estimated as the annualized slope of BP between year 0 and 5 based on linear mixed models (mean number of measurements = 4.0). Participants were then grouped into 1 of 3 categories based on the distribution of systolic BP (SBP), diastolic BP (DBP), and pulse pressure (PP) change (top 20%, middle 21-79%, bottom 20%). We calculated eGFR from cystatin C (ml/min/1.73 m2), estimated annual change in eGFR (ml/min/1.73 m2/year), and defined rapid kidney function decline as a >30% decrease in eGFR from year 5 to 10. We used multivariable logistic regression adjusting for year 0 demographic and clinical characteristics, including eGFR and BP, to determine associations of BP change with rapid kidney function decline. Median age was 59 [interquartile range (IQR): 52, 67] and median eGFR at year 0 was 95.5 (IQR: 81.7, 105.9) ml/min/1.73 m2. Median SBP at year 0 was 111, 121, and 147 mm Hg for increasing, stable, and decreasing SBP change, respectively. Increasing SBP and widening PP change were each associated with higher odds of rapid kidney function decline compared with stable SBP and PP groups, respectively [odds ratio, OR 1.7 (95% confidence interval, CI 1.3, 2.4) for SBP; OR 1.4 (95% CI 1.1, 1.9) for PP]. Decreasing SBP was associated with rapid kidney function decline after adjusting for all covariates except for year 0 BP [OR 1.4 (95% CI 1.0, 1.8)], but this association was no longer statistically significant after adjustment for year 0 BP. There were no significant associations between DBP change and rapid decline in the fully adjusted models. Similar findings were seen with annual change in eGFR. Increasing SBP and widening PP over time were associated with greater risk for accelerated kidney function decline even at BP levels below established hypertension thresholds.

From efficacy in trials to effectiveness in clinical practice: The Swedish Stroke Prevention Study

Blood pressure treatment has shown great efficacy in reducing cardiovascular events in randomized controlled trials. If this is effective in reducing cardiovascular disease in the general population, is less studied. Between 2001 and 2009 we performed an intervention to improve blood pressure control in the county of Västerbotten, using Södermanland County as a control. The intervention was directed towards primary care physicians and included lectures on blood pressure treatment, a computerized decision support system with treatment recommendations, and yearly feed back on hypertension control. Each county had approximately 255 000 inhabitants. Differences in age and incidence of cardiovascular disease were small. During follow-up, more than 400 000 patients had their blood pressure recorded. The mean number of measurements was eight per patient, yielding a total of 3.4 million blood pressure recordings. The effect of the intervention will be estimated combining the blood pressure data collected from the electronic medical records, with data on stroke, myocardial infarction and mortality from Swedish health registers. Additional variables, from health registers and Statistics Sweden, will be collected to address for confounders. The blood pressure data collected within this study will be an important asset for future epidemiological studies within the field of hypertension.

Prediagnostic Thrombocytosis Increases the Risk of Advanced Gynecological Cancer and Increases Mortality Independently of Cancer Stage – a Population-Based Study

IntroductionAn association between thrombocytosis and cancer is well established and several studies have shown that an elevated platelet count at diagnosis implies an inferior prognosis. In ovarian cancer, the pivotal role of platelets in driving the biologic mechanisms of malignant tumors has been demonstrated and paraneoplastic thrombocytosis has been shown to directly fuel tumor growth (Stone et al, N Engl J Med. 2012). In this epidemiological study, we assess the role of prediagnostic platelet levels in primary care patients subsequently diagnosed with gynecological cancer.MethodsUsing a primary care resource comprising blood differential cell counts from more than 500,000 individuals (Andersen et al, Clin Epidemiol. 2014), we included adults (18-80 years) diagnosed with gynecological cancer (ICD-10 codes C51-C58) as reported in the Danish Cancer Registry (DCR) between July 1, 2003 to January 23, 2010. We analyzed platelet counts in a 3-year period before cancer diagnosis and defined no prediagnostic thrombocytosis as a mean platelet count between 150-400x109/l, mild prediagnostic thrombocytosis as >400-550x109/l and severe prediagnosticthrombocytosis as >550x109/l.Statistical AnalysisWe used multivariable logistic regression to compute odds ratios (ORs) with 95% confidence intervals (CIs) for the association between prediagnostic thrombocytosis groups and cancer stage category (localized vs. non-localized) at the time of diagnosis (Table 1). The ORs were adjusted for known and possible confounders such as age (quadratic), year and month of blood sampling, as well as competing comorbid conditions as reported in the Danish National Patient Register. Furthermore, we analyzed time from diagnosis to all-cause mortality (as reported in the Danish Civil Registration System) in Cox regression models. The effects of prediagnostic thrombocytosis were estimated with hazard ratios (HRs) and adjusted for cancer stage category in addition to the above-mentioned confounders.ResultsA total of 1,083 women were diagnosed in the defined period comprising external female genital organs and vagina (5.1%), cervix uteri (24.8%), corpus uteri (37.2%), ovary, fallopian tube and broad ligament (32.5%) and other and unspecified female genital organs (0.4%). 614 of these patients (57%) had at least one available prediagnostic platelet measurement (mean number of measurements=1.62, SD=1.19, range=1-17) and 109 exhibited prediagnostic thrombocytosis (mild=76%, severe=24%).We observed significant associations between prediagnostic thrombocytosis and the risk of being diagnosed with advanced disease with ORs of 2.19 (1.25-3.84), P=0.006 and 3.80 (1.37-10.57), P=0.0104 for mild and severe prediagnostic thrombocytosis, respectively. The median overall survival among patients with severe prediagnostic thrombocytosis was 0.92 years, as compared with 3.34 years among those with mild prediagnostic thrombocytosis, P<0.0001 (Figure 1). When analyzing mortality rates and adjusting for cancer stage category at diagnosis, HRs were 1.52 (1.09-2.13), P=0.0145 and 3.46 (2.17-5.51), P<0.0001 for mild and severe prediagnostic thrombocytosis, respectively. Lastly, we analyzed all-cause mortality rates for localized cancer cases only and observed a significant association with severe (but not mild) prediagnostic thrombocytosis with a HR of 4.21 (1.22-14.55), P=0.032.DiscussionThis study demonstrates that prediagnostic thrombocytosis in gynecological cancer patients infers higher risks of advanced disease at time of diagnosis and inferior prognosis, not only due to the dissemination per se. In localized cancer, severe prediagnostic thrombocytosis also increases mortality with potential implications for the diagnostic work-up in these patients at initial referral to hospital.Table 1:Algorithms for cancer staging according to the TNM classificationTumor stageTNMLocalizedT1-4,x andN0 andM0T1 andN0,x andM0,xT2 andN0 andMxNon-localizedT1-4,x andN1-3 orM1UndefinedT2-4,x andNx andM0,xT3-4,x andN0 andMx [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Seasonal Variation in Home Blood Pressure Measurements and Relation to Outside Temperature in Japan

Previous studies have suggested that outside temperature affects blood pressure (BP) levels. However, recently, due to a spreading heating system, the seasonal variation in BP levels might be smaller, especially in colder seasons when more heat is used. We used continuous measurements of home BP data to track seasonal variations of BP to analyze the relation between outside temperature and BP values. Among 213 volunteers who were asked to measure BP in September 2000, 79 participants (mean age 72.7 years, 60.0% women) measured BP at least once per month until August 2003 (36 months). The mean number of measurements was 19.0 times/month. Information on outside temperature was provided by the Japan Meteorological Agency. We used general linear models to analyze the relation between outside temperature and BP values. Blood pressure levels were lowest in the warmest months. However, the highest BP levels were not observed in the coldest month, but rather in March. A clear inverse association between temperature and BP values was evident only in periods when outside temperatures were above 10°C. When the outside temperature was ≥ 10°C, 1°C increment of outside temperature correspond to 0.40 and 0.28 mmHg decrease of systolic blood pressure (SBP) and diastolic blood pressure (DBP), whereas the corresponding values were 0.06 and 0.01 mmHg when the outside temperature was <10°C. In conclusion, inverse association between outside temperature and BP was observed only in warmer seasons.

Sample size and the estimation of physiological parameters in the field

Summary Estimates of basal rate of metabolism in fruit pigeons and flying foxes, derived from the mean of individual means, were compared to the mean basal rate obtained by pooling all data into a single estimate. Pooled estimates of basal rate differ by ≤1% of the basal rates obtained from the mean of individual means in 7 of 10 species of pigeons and 4 of 11 species of flying foxes. The coefficient of variation of the mean of individual mean basal rates decreased with an increase in the mean number of measurements per individual, which, given that the number of measurements per individual was 8·4 in pigeons and 3·8 in flying foxes, partially accounts for the smaller coefficients in pigeons. The maximal absolute difference between individual mean basal rates and the mean of individual means within a species decreased with an increase in the number of measurements per individual to 8, beyond which the difference remained constant. Repeated measurements on a single individual usually gave an estimate of basal rate within 2–8% of the species’ mean when eight or more measurements were made. . The analysis of limited samples most often occurs in the study of elusive or endangered species, when the availability of individuals for study is greatly limited.

Détermination des rayons de Céphéides

We present radial velocity data for 22 galactic Cepheid stars obtained with Coravel spectrometer. Continuous observation over several years has enabled us to obtain 852 individual velocities covering all the phases of the pulsation. The mean number of measurements per star is 39, ranging from 20 to 113. For each star radial velocity versus phase diagrams have been fitted by analytical relation, and the stellar radius variation has been derived by integration of this relation over the whole period. Using recent ubv photometry of the literature and velocity curves, we have calculated the radii of the stars using a method based on the Baade-Wesselink concept. For these 22 Cepheids we give a linear logarithmic period-radius relation with a range of 2,4 to 45 days.

Decrease of ciliary beat frequency by platelet activating factor: Protective effect of ketotifen

The ciliary beat frequency (CBF) of the tracheal epithelial cells controls in part the respiratory tract mucociliary transport efficiency. We investigated the effects on CBF of PAF-acether (PAF) and its metabolite/precursor lyso-PAF. Guinea-pig tracheal rings were incubated for 3 to 6h with 1 microM PAF (C16, C18, C16/C18: 80/20%), lyso-PAF C16 or lyso-phosphatidylcholine (LPC). CBF changes were assessed by microphotooscillography (mean number of measures per ring = 14). We also examined the effect on PAF-induced CBF changes of the PAF receptor-antagonist WEB 2086, the anti-asthmatic/anti-anaphylactic drug ketotifen and the anti-histamine H1 pyribenzamine. CBF of control rings exposed to vehicle only from 0 to 6h showed no significant statistical variations (hertz, mean +/- SEM): 10.8 +/- 0.1 (n of measures = 890). By contrast, 1 microM C16, C18, and C16/C18 PAF significantly inhibited CBF after 3 to 6h incubation. C16 and C16/C18 PAF were more potent than C18 PAF (8.8 +/- 0.2, n = 112, 8.7 +/- 0.2, n = 64, and 9.6 +/- 0.1, n = 537 respectively; ANOVA analysis, p < 0.001 from control). At the same concentration, lyso-PAF also inhibited CBF, 9.5 +/- 0.1 (n = 197, p < 0.001) but not LPC, 10.5 +/- 0.2 (n = 127). WEB 2086 inhibited lyso-PAF and C16/18 PAF-induced CBF decrease. Preincubation (20 min) with ketotifen but not with pyribenzamine (1 microM) also suppressed the CBF inhibitory effect of PAF and lyso-PAF. Incubation of [3H]PAF with tracheal rings from 10 min to 6h resulted in its partial metabolism (25%) into [3H]lyso-PAF and a compound with a short retention time (10 min). [3H]lyso-PAF incubated for 3h with tracheal rings was partially metabolized (10%) into [3H]PAF and a compound with a short retention time. The PAF-induced decrease of CBF is congruent with its influence on pulmonary clearance, possibly via a specific receptor, since WEB 2086 abolished the effect of PAF. The inhibition of the PAF-induced CBF decrease by ketotifen may contribute to the therapeutic properties of this antiallergic drug.

Longitudinal Survey of Loa loa Filariasis in Southern Cameroon: Long-Term Stability and Factors Influencing Individual Microfilarial Status

A longitudinal, one-year survey of Loa loa infection was carried out in an endemic area of southern Cameroon. Parasitologic samplings (calibrated thick blood smears) were performed every two months to study the evolution of loiasis infection at both the population and the individual level. The mean number of measurements by subject was 3.8 (range 1-6). At the population level, prevalence of infection and microfilarial load were found to be very stable over time. This observation is consistent with the existence of an important reserve of parasitic material available for vectors and the maintenance of high levels of transmission. At the individual level, both the microfilarial status (microfilaremic/nonmicrofilaremic) and the level of parasitemia showed a remarkable stability over time. Age was the relevant factor that influenced the individual microfilarial status in the whole population. When only microfilaremic individuals were taken into account, age did not influence the level of microfilaremia, suggesting that loiasis could be considered as a noncumulative disease. The stability of individual microfilarial status and the pattern of infection variations observed with age support the view that genetic factors might be involved in host defense mechanisms against loiasis infection.

Sequential Analysis in a Bayesian Model of Diastolic Blood Pressure Measurement

A sequential method for diagnosing or excluding hypertension based on the Bayesian model of diastolic blood pressure presented in a companion article is presented. The likelihood ratio method of Wald is modified to include the effects of a prior probability distribution and to constrain the strategy to achieve specified positive and negative predictive values. The resulting formulas for upper and lower limits to diagnose and exclude diastolic hypertension can be evaluated using a hand calculator and a table of areas of the standard normal distribution. The strategy is illustrated for a population having a blood pressure distribution similar to that of the cohort screened for participation in the Hypertension Detection and Follow-up Program, with 90 mm Hg as the cutoff defining hypertension and required positive and negative predictive values of 95%. The performance of the strategy was simulated using Monte Carlo methods. The median number of readings required for diagnosis is three, and 80% of subjects are diagnosed in 11 or fewer readings. In contrast to the strategy's 95% predictive values, a fixed-number-of-measurements strategy requiring the same mean number of measurements has a positive predictive value of only 83% and a negative predictive value of 96%. When the parameters of the model have been properly measured or estimated, this method is practical, efficient, and accurate for diagnosing hypertension in a known population.