Questions tagged [cluster-sample]

Cluster sampling is a sampling design in which the observation units have to be grouped together for logistical reasons (e.g., students clustered in schools or households clustered in a geographic area). Typically, cluster samples are multistage samples, so geographic areas are selected in the first stage and households in the subsequent stage.

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10 views

How can I apply a design effect of 2 on my fisher's test and/or regression?

I'm trying to use R or statistical analysis on a multicluster sampling and specifically to inform it that I have a design effect of 2. I've familiarised myself with the survey package and tried to ...
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5 views

performing a multilevel logistic regression: data naturally clustered but small clusters, singletons and limited number of 2nd level clusters: help?

I am looking to perform a binomial regression calculating the reselection chances of parliamentarians in the European Parliament based on their activity levels. DV= reselection: 0/1. My data is ...
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23 views

Derive an expression to estimate the total number of clusters N, with unequal cluster sample sizes m

The task in the question below is to determine the number of clusters required for a "cluster randomised crossover" design conducted over two 6-month periods, with m = subjects per cluster per period, ...
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CLUSTER SAMPLING PROOF

i have one questions that referred to book "On Efficiency of Cluster Sampling" (Daroga Singh, 1956) and my problem is i don't have that book, 9.14 The following sampling schemes for estimating the ...
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41 views

How can I model clustered data in a regression?

I have a dataset of $N=3000$ biopsies from humans, each of which have an outcome I am trying to examine using covariates of the patient who provided the biopsy. Some biopsies from the same patient ...
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Prevalence estimate within clustered sample?

This study has a one stage clustered sample of households, there are 707 households and everyone in the household is included so the total n=2272. I would like to find the prevalence of positive ...
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47 views

What regression model to use for both repeated measurements and cluster data (and how to do it in R)?

My research question involves looking at association between the characteristics of neighborhoods (% male, % female, income, % young people, % old people) and the participation rate in a programme (% -...
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29 views

Two-stage stratified cluster sampling with “overlapping” PSUs

Let's say I want to do a survey getting a representative sample for an entire population P, as well as groups A and ...
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27 views

Sample size calculation with cluster randomization for within subjects design

I'm in the process of planning a two group between subjects experiment and I want to calculate the required sample size. As the population I want to examine is not very large, it is rather ...
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15 views

Multilevel versus clusteredness in the sample

does anyone can explain to me the main differences between multilevel estimations and clustering correction? I think with HLM technique we can get estimation to the random parameters (the group level ...
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37 views

Estimate the total number of retired residents in the city and place a bound on the error of estimation

I am study for my upcoming stats exam and I came across this quesiton: Suppose a sociologist wants to estimate the total number of retired people residing in a certain city. She decides to sample ...
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29 views

Why is the equation for Intra-class correlation aligned with design effect of cluster sampling?

The design effect definition (link) is: $$ DEFF = 1+ (m-1)*ICC $$ It is also the relationship between the variance of estimating the mean with the cluster sampling divided by the variance if the ...
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224 views

Regression model with aggregated targets

Similar as in this self-answered question, I want to ask about possible approaches for modelling data with aggregated targets, i.e. things like $$ \bar y_{j[i]} = \alpha + \beta x_i + \varepsilon_i $$...
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58 views

Is it necessary to fit cluster-level covariates for mixed models?

Suppose I have the following two generalized linear mixed models (GLMM): \begin{align*} g(\mathbb{E}[Y_{ij}|X_{ij}]) &= \beta^\intercal_1 X_{ij}^{(1)} + \beta_2^\intercal X_{i}^{(2)} + U_i &&...
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What is the procedure for conducting a power analysis for regressions with clustered standard errors?

I am wanting to carry out an OLS regression with 5 predictor variables across 10 traits, with each row in my data consisting of a combination of participant and trait, so each participant will have 10 ...
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45 views

SMD meta-analysis including cluster-randomised trials: is it possible? If so, how?

Where we have cluster-adjusted results from trials (summary statistics), under what circumstances can we include them in a standardised mean difference (SMD) meta-analysis and which calculations are ...
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28 views

Balanced randomization within clusters

I was hoping someone could point me in the right direction on a randomization method. We want to randomize teachers to receive an educational intervention. The catch is that we have a number of ...
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43 views

How to know whether a random effect or a cluster effect is necessary for a mixed effect logistic regression?

I have 8 variables in my model out of which I have a group which is definitely not a fixed effect. I tried checking the random effect on the basis of the log-likehood test and it seems significant. I ...
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IPD meta-analysis: need to weight regression and population level estimates?

Using individual patient data (IPD) from various studies, do I need to weight observations in a meta-analysis? Each study used a two-stage cluster sampling design with uniform samples per cluster and ...
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117 views

Confidence intervals for survey-weighted Poisson regression in R where counts are totals of the survey weights

Forgive me if this is a very basic question. I am using a large database of healthcare encounters that uses a stratified sampling approach. Each row in the database is a sampled encounter, and has a ...
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59 views

Calculating Sample Size for Cluster Randomized Trials with Person-level or Cluster-Level Outcomes

I have been looking for a formula to calculate the estimated sample size for a two-level cluster-randomized controlled trial with cluster-level outcome data. To my reading, several authors do not make ...
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25 views

Single DV with repeated/clustered measurements of IV

I have an analytical dilemma wherein I have a single DV with multiple categorical and continuous IVs (one of which is a continuous IV that has multiple measurements across time). I'm not sure the best ...
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Why doesn't clustering bias the standard errors in this very simple simulation?

I simulate a very simple model with one regressor and a random intercept: $$y_{ij} = \beta_0 + \beta_1x_{1,ij} + u_j + \epsilon_{ij}$$ I run model <- lm(y ~ x1) ...
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152 views

Power Calculation in R for CRCT with outcome on individual level

I would welcome any help with computing power calculations for cluster randomised control trial and specifying the code in R for this. I've been trying to use clusterPower package but any R package ...
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51 views

Sufficient sampling size for logistical regression observational data

As a part of my master thesis, I'm conducting an observational study of journalists' background and the effect of this on the approach to a certain case study. I have a fixed number of observations/...
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229 views

Clusters in Cluster Analysis and Sampling

In Cluster Analysis, clusters are usually "homogenous within" (that is, units within a cluster are close to each other ) and "heterogeneous within" (or clusters far from each other). In Survey ...
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74 views

Linear mixed effects model for twins

I have a dataset which contains data on MZ twins, DZ twins and unrelated individuals. The predictor and response are binomial variables and the effect size of the predictor may vary depending on the ...
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How to estimate variance for identical & fraternal twins with a mixed model

I am using the twins data from OpenMx and am curious to estimate the empirical covariance structure for BMI differences in monozygous and dizygous twins: ...
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1answer
1k views

Causes for Underdispersion in Poisson Regression

I am working with count data (number of pregnancies per woman), and using glm Poisson (log-link) to model determinants of the former count variable. From simple descriptives I observe that my data ...
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308 views

GEE with independent working correlation matrix vs GLM on twin pairs yield different confidence intervals

I have a data set with about 2000 twin pairs and want to apply a logistic regression to it while taking account of the correlated observations (twin pairs = clusters). I use the GEE procedure in SPSS. ...
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2answers
112 views

GEE all clusters of size 1 have same outcome

I have a large population of patients and hospitalization (>1 million) information. I'm trying to look at the relationships between various predictors and hospital re-admissions within 30 days. The ...
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31 views

How can I account for clusters at different observational levels than the independent variable?

My independent variable, $Y_i$, has observations at the group-year level. However, I know $Y_i$ is not independent for all $i$ because the same individuals will be in a group for several years in a ...
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904 views

Standard Error For Cluster Sampling

A problem I've found and been thinking about for a while but not sure I can articulate properly. Any help appreciated. A survey is being planned with the goal of interviewing $n$ people ...
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1answer
44 views

Random sampling with different stages

I'd appreciate some help solving this sampling issue: I have select a random sample of people for a survey in a certain country. The country is divided in 6 regions. In total, there are 981 ...
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49 views

Sample size calculation of a national study

We want to conduct a national study to estimate a prevalence of certain disease. we still confused about the sample size calculation and the criteria of selecting a representative sample. First: is ...
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2answers
274 views

Robust Variance Estimate with Cox model in Complex Survey Setting

I have a single-stage cluster sample, and I am trying to estimate the hazard ratio of a given exposure after controlling for a confounder. My dataset contains 10 strata, with 20 clusters within each ...
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1answer
1k views

Does # of observations in each cluster matter for cluster-robust standard errors?

In multiple regression with panel data, when calculating cluster robust standard errors, does it matter if there are only a handful of observations in each cluster? I am looking at if the ...
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204 views

Analysis of a cluster crossover design

I am analyzing data from a cluster randomized cross over trial. There are 9 clusters and 3 periods in the data. The clusters are dental clinics and in each period different patients are sampled. I ...
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250 views

Are clusters in cluster sampling made randomly?

Knowing that in cluster sampling the population is divided into clusters and a simple random sample is taken of them and then all the elements of the chosen clusters are sampled, are the clusters in ...
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617 views

Sample size calculation for Cluster randomized trial

In the following Paper by Clare Rutterford, Andrew Copas and Sandra Eldridge, the following formula is given for sample size calculation: assuming the following properties: • m - number of clusters ...
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102 views

Which bootstrap for small set of independent data?

I am thinking which bootstrap to choose for studying MIT-BIH arrythmia database (44 patients) in time-domain and Fourier-domain. I need to find a variable which can allow me to determine ...
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1answer
58 views

Identifying a single cluster from multiple clusters per customer

Although I have worked out several possible approaches, am curious if anyone has a better best practice to recommend? I have a large set of customer events (online behavior: 1 mil. records, 20 ...
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230 views

For boostrapping: stratified or cluster sampling?

I am trying to apply bootstrapping on several regression models to obtain SEs of parameters. My question is about preparing the bootstrapping samples in proper manner. The data I am working on are ...
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28 views

How do I determine the necessary sample size for this data?

I want to estimate enlistment of African American soldiers in the Union Army (during the American Civil War) by county in order to regress this variable on county-level post-war outcomes. I ultimately ...
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87 views

How to calculate a sample size in the case of a stratified 3 degrees sample design ?

I am trying to calculate the sample size (and the repartition between PSUs and SSUs) needed to obtain an estimation of a proportion (that I assume to de around 50%) with a 0.05 standard error in the ...
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279 views

Survival analysis for patients that have been subjected to multiple treatments

I have data for patients that were subjected to either one treatment or multiple treatments at various points in time and I need to analyse their survival times after treatments. This of course means ...
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186 views

Expectation Value of Standard Deviation from “k” Closest Samples

The question that I'm am trying to answer is how to determine the expectation value of the standard deviation of 'k' closest samples to value 'A'. The standard deviation and mean of the underlying ...
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51 views

How to analyse paired data lacking pairing information? [duplicate]

A colleague has a dataset from a before and after study looking at a continuous outcome that was measured in individuals before and after an intervention. An unknown but not insubstantial proportion ...
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71 views

Is controlling for cluster good enough in an analysis with a clustered sample?

I'm trying to understand how sampling design affects analyses and I'm a little confused about how to adjust for clustering. From what I've read, when you have a clustered sample you are supposed to ...
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295 views

one sample t test for clustered data in R

How shall I do one sample t test for clustered data? For instance, I have N = 100 number of observations, which are obtained from 5 different regions. I'd like to test whether the outcome y is ...