Single-stage cluster sampling: Clusters of equal size

Similar to strata, population units may instead be grouped into clusters. Usually, units within clusters are geographically or genetically close to one another—all households on a city block, individuals within a single family. In (single-stage) equal size cluster sampling, the total population consists of N clusters, with equal numbers of population units within each cluster. A sample of n clusters is selected by SRS, y values of all population units within clusters are measured, and an unbiased estimator of the population mean is the simple average of cluster means in the sample. An ANOVA sum of squares partition can be used to show that this strategy will outperform SRS with mean-per-unit estimation whenever the mean square between clusters is less than the finite population variance. This means that it is desirable for clusters to have similar means but a great deal of variability within clusters, a contrast with the desirable characteristics of strata (little variability within strata, substantial difference between stratum means). Many methods of collection of samples in fisheries (seines, nets) and wildlife (mist nets, live traps) involve collection of individuals as clusters. Unfortunately, clusters (e.g., human families) often consist of closely related or similar individuals. Because within cluster variation is often relatively low, it is often advantageous and cost-effective to instead adopt two-stage cluster sampling (considered in Chapter 9) for which only a sample of units within each selected cluster are examined, thereby allowing more clusters to be examined for the same total survey cost.

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Addition of Flucytosine to Fluconazole for the Treatment of Cryptococcal Meningitis in Africa: A Multicountry Cost-effectiveness Analysis

Clinical Infectious Diseases ◽

10.1093/cid/ciz163 ◽

2019 ◽

Vol 70 (1) ◽

pp. 26-29 ◽

Cited By ~ 3

Author(s):

Tinevimbo Shiri ◽

Angela Loyse ◽

Lawrence Mwenge ◽

Tao Chen ◽

Shabir Lakhi ◽

...

Keyword(s):

Sensitivity Analysis ◽

Cost Effectiveness ◽

Cryptococcal Meningitis ◽

Cost Effective ◽

Immunodeficiency Virus ◽

The Mean ◽

The Cost ◽

The Impact ◽

Costing Analysis ◽

Very High

Abstract Background Mortality from cryptococcal meningitis remains very high in Africa. In the Advancing Cryptococcal Meningitis Treatment for Africa (ACTA) trial, 2 weeks of fluconazole (FLU) plus flucytosine (5FC) was as effective and less costly than 2 weeks of amphotericin-based regimens. However, many African settings treat with FLU monotherapy, and the cost-effectiveness of adding 5FC to FLU is uncertain. Methods The effectiveness and costs of FLU+5FC were taken from ACTA, which included a costing analysis at the Zambian site. The effectiveness of FLU was derived from cohorts of consecutively enrolled patients, managed in respects other than drug therapy, as were participants in ACTA. FLU costs were derived from costs of FLU+5FC in ACTA, by subtracting 5FC drug and monitoring costs. The cost-effectiveness of FLU+5FC vs FLU alone was measured as the incremental cost-effectiveness ratio (ICER). A probabilistic sensitivity analysis assessed uncertainties and a bivariate deterministic sensitivity analysis examined the impact of varying mortality and 5FC drug costs on the ICER. Results The mean costs per patient were US $847 (95% confidence interval [CI] $776–927) for FLU+5FC, and US $628 (95% CI $557–709) for FLU. The 10-week mortality rate was 35.1% (95% CI 28.9–41.7%) with FLU+5FC and 53.8% (95% CI 43.1–64.1%) with FLU. At the current 5FC price of US $1.30 per 500 mg tablet, the ICER of 5FC+FLU versus FLU alone was US $65 (95% CI $28–208) per life-year saved. Reducing the 5FC cost to between US $0.80 and US $0.40 per 500 mg resulted in an ICER between US $44 and US $28 per life-year saved. Conclusions The addition of 5FC to FLU is cost-effective for cryptococcal meningitis treatment in Africa and, if made available widely, could substantially reduce mortality rates among human immunodeficiency virus–infected persons in Africa.

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A comparison of soil sampling procedures used to monitor soil fertility in permanent pastures

Soil Research ◽

10.1071/sr9840081 ◽

1984 ◽

Vol 22 (1) ◽

pp. 81 ◽

Cited By ~ 16

Author(s):

DK Friesen ◽

GJ Blair

Keyword(s):

Sampling Method ◽

Nutrient Status ◽

Temporal Variations ◽

Cluster Sampling ◽

Soil Test ◽

Sampling Strategies ◽

Grazed Pasture ◽

The Mean ◽

Sampling Procedures ◽

Bray 1

Soil testing programs are often brought in disrepute by unexplained variability in the data. The deposition of dung and urine onto grazed pasture brings about marked variation in the chemical status of soils which contributes to this variability. A study was undertaken to compare a range of sampling procedures to estimate Colwell-P, Bray-1 P, bicarbonate K and pH levels in adjacent low and high P status paddocks. The sampling strategies used consisted of 75 by 50 m grids; whole and stratified paddock zig-zag and cluster (monitor plot) samplings. Soil test means for the various parameters did not vary among sampling methods. The number of grid samples required to estimate within 10% of the mean varied from 121 for Bray-1 P down to 1 for soil pH. Sampling efficiencies were higher for cluster sampling than for whole paddock zig-zag path sampling. Stratification generally did not improve sampling efficiency in these paddocks. Soil test means declined as sampling depth increased, but the coefficient of variation remained constant for Colwell-P and pH. The results indicate that cluster sampling (monitor plots) is the most appropriate procedure for estimating the nutrient status of grazed pastures. This sampling method enables a more accurate measure to be taken of the nutrient status of a paddock and should allow more reasonable estimates to be made of the temporal variations in soil test.

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A Novel Nonsurgical Technique for Correcting Congenital Auricular Anomalies

Facial Plastic Surgery ◽

10.1055/s-0041-1735976 ◽

2021 ◽

Author(s):

Shay I. Duvdevani ◽

Hadas Knoller ◽

Noa Rozendorn ◽

Eran E. Alon ◽

Ory Madgar

Keyword(s):

Treatment Initiation ◽

Neonatal Period ◽

Cost Effective ◽

Normal Appearance ◽

Time Saving ◽

Effective Time ◽

Custom Made ◽

The Mean ◽

Ear Anomalies ◽

Surgical Corrections

AbstractCongenital ear anomalies are associated with psychological morbidity. Ear deformities can usually be corrected by nonsurgical techniques such as splinting or molding in the neonatal period, initiated before 6 weeks. Without early corrections, many will require otoplasty during childhood. We introduce a novel silicone-based custom mold technique for congenital ear anomalies. The highly malleable silicone was pushed into every part of the auricle, enabling the auricle to remain in the desired shape, with new molds made weekly. Of 31 newborns (18 males, 13 females), 54 ears were treated. Average age at treatment initiation was 26.8 days. The mean treatment duration was 43.2 days, with a median of 28 days. Normal appearance and parent's satisfaction were achieved in 30 patients with 49 deformed ears and also in four newborns older than 6 weeks. Three concha type microtia in two patients achieved great improvements and parents' satisfaction. No complications were reported. Marked aesthetic improvements and normal appearance were achieved for all deformed auricles treated, and improvements in the concha type microtia will partially alleviate future surgical corrections. The results are not inferior to other techniques. The advantages are as follows: cost-effective, time-saving, simple to master, no need for hair shaving, and easy use for parents. Patients older than 6 weeks of age achieved normal auricle appearance, enabling the correction in older newborns. Custom made silicone auricle molding offers a simple nonsurgical technique for correcting congenital ear anomalies, alleviating the need for future surgical corrections.

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Cost-effectiveness of positive airway pressure modalities in obesity hypoventilation syndrome with severe obstructive sleep apnoea

Thorax ◽

10.1136/thoraxjnl-2019-213622 ◽

2020 ◽

Vol 75 (6) ◽

pp. 459-467 ◽

Cited By ~ 4

Author(s):

Juan F Masa ◽

Babak Mokhlesi ◽

Iván Benítez ◽

Francisco Javier Gómez de Terreros Caro ◽

M-Ángeles Sánchez-Quiroga ◽

...

Keyword(s):

Cost Effectiveness ◽

Primary Outcome ◽

Cost Effective ◽

Sleep Apnoea ◽

Obesity Hypoventilation Syndrome ◽

Obstructive Sleep ◽

The Mean ◽

Hypoventilation Syndrome ◽

Obesity Hypoventilation

BackgroundObesity hypoventilation syndrome (OHS) is treated with either non-invasive ventilation (NIV) or CPAP, but there are no long-term cost-effectiveness studies comparing the two treatment modalities.ObjectivesWe performed a large, multicentre, randomised, open-label controlled study to determine the comparative long-term cost and effectiveness of NIV versus CPAP in patients with OHS with severe obstructive sleep apnoea (OSA) using hospitalisation days as the primary outcome measure.MethodsHospital resource utilisation and within trial costs were evaluated against the difference in effectiveness based on the primary outcome (hospitalisation days/year, transformed and non-transformed in monetary term). Costs and effectiveness were estimated from a log-normal distribution using a Bayesian approach. A secondary analysis by adherence subgroups was performed.ResultsIn total, 363 patients were selected, 215 were randomised and 202 were available for the analysis. The median (IQR) follow-up was 3.01 (2.91–3.14) years for NIV group and 3.00 (2.92–3.17) years for CPAP. The mean (SD) Bayesian estimated hospital days was 2.13 (0.73) for CPAP and 1.89 (0.78) for NIV. The mean (SD) Bayesian estimated cost per patient/year in the NIV arm, excluding hospitalisation costs, was €2075.98 (91.6), which was higher than the cost in the CPAP arm of €1219.06 (52.3); mean difference €857.6 (105.5). CPAP was more cost-effective than NIV (99.5% probability) because longer hospital stay in the CPAP arm was compensated for by its lower costs. Similar findings were observed in the high and low adherence subgroups.ConclusionCPAP is more cost-effective than NIV; therefore, CPAP should be the preferred treatment for patients with OHS with severe OSA.Trial registration numberNCT01405976

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Inhibition of Cytochrome P450 (CYP450) Isoforms by Isoniazid: Potent Inhibition of CYP2C19 and CYP3A

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.45.2.382-392.2001 ◽

2001 ◽

Vol 45 (2) ◽

pp. 382-392 ◽

Cited By ~ 112

Author(s):

Zeruesenay Desta ◽

Nadia V. Soukhova ◽

David A. Flockhart

Keyword(s):

Cytochrome P450 ◽

Liver Microsomes ◽

Cost Effective ◽

Competitive Inhibitor ◽

Inhibitory Effect ◽

Significant Inhibition ◽

Specific Substrate ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

The Mean

ABSTRACT Isoniazid (INH) remains the most safe and cost-effective drug for the treatment and prophylaxis of tuberculosis. The use of INH has increased over the past years, largely as a result of the coepidemic of human immunodeficiency virus infection. It is frequently given chronically to critically ill patients who are coprescribed multiple medications. The ability of INH to elevate the concentrations in plasma and/or toxicity of coadministered drugs, including those of narrow therapeutic range (e.g., phenytoin), has been documented in humans, but the mechanisms involved are not well understood. Using human liver microsomes (HLMs), we tested the inhibitory effect of INH on the activity of common drug-metabolizing human cytochrome P450 (CYP450) isoforms using isoform-specific substrate probe reactions. Incubation experiments were performed at a single concentration of each substrate probe at its Km value with a range of INH concentrations. CYP2C19 and CYP3A were inhibited potently by INH in a concentration-dependent manner. At 50 μM INH (∼6.86 μg/ml), the activities of these isoforms decreased by ∼40%. INH did not show significant inhibition (<10% at 50 μM) of other isoforms (CYP2C9, CYP1A2, and CYP2D6). To accurately estimate the inhibition constants (Ki values) for each isoform, four concentrations of INH were incubated across a range of five concentrations of specific substrate probes. The meanKi values (± standard deviation) for the inhibition of CYP2C19 by INH in HLMs and recombinant human CYP2C19 were 25.4 ± 6.2 and 13 ± 2.4 μM, respectively. INH showed potent noncompetitive inhibition of CYP3A (Ki = 51.8 ± 2.5 to 75.9 ± 7.8 μM, depending on the substrate used). INH was a weak noncompetitive inhibitor of CYP2E1 (Ki = 110 ± 33 μM) and a competitive inhibitor of CYP2D6 (Ki = 126 ± 23 μM), but the mean Ki values for the inhibition of CYP2C9 and CYP1A2 were above 500 μM. Inhibition of one or both CYP2C19 and CYP3A isoforms is the likely mechanism by which INH slows the elimination of coadministered drugs, including phenytoin, carbamazepine, diazepam, triazolam, and primidone. Slow acetylators of INH may be at greater risk for adverse drug interactions, as the degree of inhibition was concentration dependent. These data provide a rational basis for understanding drug interaction with INH and predict that other drugs metabolized by these two enzymes may also interact.

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The cost of immunising at the general practice level

Journal of Primary Health Care ◽

10.1071/hc09286 ◽

2009 ◽

Vol 1 (4) ◽

pp. 286 ◽

Cited By ~ 6

Author(s):

Nikki Turner ◽

Paul Rouse ◽

Stacey Airey ◽

Helen Petousis-Harris

Keyword(s):

General Practice ◽

Cost Allocation ◽

Cost Model ◽

Cost Effective ◽

Fee For Service ◽

Activity Based Costing ◽

Childhood Immunisation ◽

Practice Nurses ◽

The Mean ◽

The Cost

INTRODUCTION: Childhood immunisation is one of the most cost-effective activities in health care. However, New Zealand (NZ) has failed to achieve national coverage targets. NZ general practice is the primary site of service delivery and is funded on a fee-for-service basis for delivery of immunisation events. AIM: To determine the average cost to a general practice of delivering childhood immunisation events and to develop a cost model for the typical practice. METHODS: A purposeful selection of 24 diverse practices provided data via questionnaires and a daily log over a week. Costs were modelled using activity-based costing. RESULTS: The mean time spent on an immunisation activity was 23.8 minutes, with 90.7% of all staff time provided by practice nurses. Only 2% of the total time recorded was spent on childhood immunisation opportunistic activities. Practice nurses spent 15% of their total work time on immunisation activity. The mean estimated cost per vaccination event was $25.90; however, there was considerable variability across practices. A ‘typical practice’ model was developed to better understand costs at different levels of activity. CONCLUSIONS: The current level of immunisation benefit subsidy is considerably lower than the cost of a standard vaccination event, although there is wide variability across practices. The costs of delivery exceeding the subsidy may be one reason why there is an apparently small amount of time spent on extra opportunistic activities and a barrier to increasing efforts to raise immunisation rates. KEYWORDS: Immunisation; vaccination; patient care management; cost analysis; cost allocation

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Cost-Effectiveness Analysis of Biopharmaceuticals for Treating Rheumatoid Arthritis: Infliximab, Adalimumab, and Etanercept

BioMed Research International ◽

10.1155/2021/4450162 ◽

2021 ◽

Vol 2021 ◽

pp. 1-12

Author(s):

Ahmad Gholami ◽

Jassem Azizpoor ◽

Elham Aflaki ◽

Mehdi Rezaee ◽

Khosro Keshavarz

Keyword(s):

Rheumatoid Arthritis ◽

Sensitivity Analysis ◽

Cost Effectiveness ◽

Cost Effective ◽

The Other ◽

Cost Data ◽

Fars Province ◽

Study Results ◽

The Mean ◽

The Cost

Introduction. Rheumatoid arthritis (RA) is a chronic progressive inflammatory disease that causes joint destruction. The condition imposes a significant economic burden on patients and societies. The present study is aimed at evaluating the cost-effectiveness of Infliximab, Adalimumab, and Etanercept in treating rheumatoid arthritis in Iran. Methods. This is a cost-effectiveness study of economic evaluation in which the Markov model was used. The study was carried out on 154 patients with rheumatoid arthritis in Fars province taking Infliximab, Adalimumab, and Etanercept. The patients were selected through sampling. In this study, the cost data were collected from a community perspective, and the outcomes were the mean reductions in DAS-28 and QALY. The cost data collection form and the EQ-5D questionnaire were also used to collect the required data. The results were presented in the form of an incremental cost-effectiveness ratio, and the sensitivity analysis was used to measure the robustness of the study results. The TreeAge Pro and Excel softwares were used to analyze the collected data. Results. The results showed that the mean costs and the QALY rates in the Infliximab, Adalimumab, and Etanercept arms were $ 79,518.33 and 12.34, $ 91,695.59 and 13.25, and $ 87,440.92 and 11.79, respectively. The one-way sensitivity analysis confirmed the robustness of the results. In addition, the results of the probabilistic sensitivity analysis (PSA) indicated that on the cost-effectiveness acceptability curve, Infliximab was in the acceptance area and below the threshold in 77% of simulations. The scatter plot was in the mentioned area in 81% and 91% of simulations compared with Adalimumab and Etanercept, respectively, implying lower costs and higher effectiveness than the other two alternatives. Therefore, the strategy was more cost-effective. Conclusion. According to the results of this study, Infliximab was more cost-effective than the other two medications. Therefore, it is recommended that physicians use this medication as the priority in treating rheumatoid arthritis. It is also suggested that health policymakers consider the present study results in preparing treatment guidelines for RA.

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EFFICACY OF LATERAL WEDGING IN FOOTWEAR IN MEDIAL COMPARTMENT OSTEOARTHRITIS KNEE

10.36106/paripex/8300399 ◽

2019 ◽

pp. 1-3

Author(s):

Suman Badhal ◽

U. Singh ◽

S. L Yadav ◽

Gita Handa

Keyword(s):

Intervention Group ◽

Cost Effective ◽

Mean Difference ◽

Medial Compartment ◽

Treatment Modalities ◽

Rank Test ◽

P Value ◽

Knee Oa ◽

The Mean ◽

Group B

INTRODUCTION: In Knee osteoarthritis (OA) Shoe modifications, such as lateral-wedge insoles or shock absorbing shoes with insoles, have been recommended for conservative therapy of mild knee OA but with little objective data on Indian patients. OBJECTIVE : this prospective study was done to study the effect of lateral heel sole wedging (insole) in the patients of OA of knee (medial compartment) and its relation to function,pain and stiffness parameters status on VAS and WOMAC scale and to see the requirement of the number of Aceclofenac tablets. METHODS: 60 patients fulfilling the inclusion criteria were enrolled and divided into intervention group A (30) and nonintervention Group B (30) with random allocation.Paired t-test,Wilcoxon sign rank test and Man Whitney U test were applied at significant p-value of <0.05%. RESULTS: the reduction of mean difference in pain on VAS and WOMAC scale, improvement in Mean difference in function parameters the mean reduction of pain in standing/ walking,bending and ascending/descending at WOMAC scale was significantly higher in intervention group. Also the mean reduction in the need for aceclofenac was significantly lower in intervention group evident from fourth week onward to fifth and sixth week.Conclusion:The lateral wedging in shoes in medial joint osteoarthritis is beneficial and it can be cost-effective conservative treatment modalities in early osteoarthritis patients, particularly in developing countries as it can reduces the requirement of NSAIDS and improve functional level of patients by reducing pain in various activities.

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How managers can reduce household water use through communication: A field experiment

10.31234/osf.io/j5v6y ◽

2020 ◽

Author(s):

Heather Hodges ◽

Colin Kuehl ◽

Sarah E. Anderson ◽

Phillip John Ehret ◽

Cameron Brick

Keyword(s):

Field Experiment ◽

Water Use ◽

Cost Effective ◽

High Water ◽

Single Family ◽

Residential Water Use ◽

Household Water ◽

Average Water ◽

Water District ◽

Residential Water

As populations increase and droughts intensify, water providers are using tools such as persuasive messaging to decrease residential water use. However, district-led messaging campaigns are rarely informed by psychological science, evaluated for effectiveness, or strategically disseminated. In collaboration with a water district, we report a field experiment among single-family households using persuasive messaging based on the information-motivation-behavioral skills model (IMB). We randomly assigned 10,000 households to receive different mailings and measured household water use. All messaging reduced water consumption relative to the control. On average, water use dropped 0.68 HCF (509 gallons) per household in the first month. Had all 10,000 single-family, occupied, non-agricultural residences been mailed the IMB messaging, more than 5 million gallons would have been saved in the first month. The effects declined but persisted for approximately three months and were three to six times greater in households with high water use (75th-90th percentiles) relative to average water use. These findings suggest that combining message elements from the IMB model can reduce residential water use and that targeting high-use households is particularly cost-effective.

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Interpreter proxy versus healthcare interpreter for administration of patient surveys following arthroplasty: a pilot study

10.21203/rs.2.12241/v2 ◽

2019 ◽

Author(s):

Daniel Xue ◽

Timothy Churches ◽

Elizabeth Armstrong ◽

Rajat Mittal ◽

Justine M. Naylor ◽

...

Keyword(s):

Limited English Proficiency ◽

Surgical Complication ◽

Intraclass Correlation ◽

Cost Effective ◽

Post Discharge ◽

Patient Reported ◽

Reported Health ◽

The Mean ◽

First Interview ◽

Score Range

Abstract Purpose: Clinical quality registries and other systems that conduct routine post-discharge surveillance of patient outcomes following surgery may have difficulty surveying patients who have limited proficiency in the language of the healthcare provider. Interpreter proxies (family and carers) are often used due to limited access to certified healthcare interpreters (due to cost or availability). The aim of this study was to assess the reliability of engaging interpreter proxies compared with certified healthcare interpreters for the administration of patient-reported health-related surveys for people with limited English proficiency (LEP). Methods: People with LEP and due for a routine 6-month telephone follow-up post knee or hip arthroplasty were invited to participate. Participants were randomly allocated to having their first interview with an interpreter proxy or a certified healthcare interpreter followed by the second (crossover) interview within 2 weeks (range: 4 to 12 days) after the first interview using the alternative method. Agreement between the two methods was assessed using quadratic weighted Cohen's kappa, intraclass correlation and concordance correlation co-efficient where appropriate for EQ-5D health domains, total Oxford hip and knee scores, patient satisfaction, operation success, readmission, reoperation, and post-surgical complication responses. The mean of the differences between the same data items collected by each of the two methods was also calculated. Results: 85 participants (96%) completed the study. There was substantial to excellent inter-rater agreement (kappa=0.69-0.87 and ICCs above 0.74) for all but one measure. The mean differences between family proxy and healthcare interpreter scores for each participant were small, ranging from 0.01 (score range of 1-5) to 0.72 (score range of 0-100). Conclusion: These results suggest that using interpreter proxies is a reliable alternative to certified healthcare interpreters in conducting patient-reported health surveys, potentially making this process easier and cost effective for researchers and registries.

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