Questions tagged [matching]

Matching refers to a process in experimental design in which observations are sampled in a systematic, non-random fashion to be analyzed more efficiently with special statistical methods.

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The appropriate match ratio between case and controls: the obsession with 1:5 [duplicate]

My intention with this question is to collect relevant references or literature for a recurrent methodological approach commonly applied in health research. The main question is: what is the ...
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Constructing ordinal variable for matching

I know for all the firms in my data how the R&D budget is allocated to three distinct groups based on how applied the research is. For example for firm X I know: 10% of R&D budget is spend on ...
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Add samples to given set to match distribution

I have a distribution from which I can draw random (iid) samples. I also have a (non-random) "sample" from that distribution that is given and skews heavily towards the lower end of it. I would now ...
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44 views

Why and how to match variables using logistic regression?

I have a dataset of ~4.7K records focused on binary classification with 60 features. class 1 is of 1554 records and class 2 is ...
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23 views

Kernel Matching

I wish to estimate a treatment effect using Kernel Matching, but I'm confused about the process. From a high level, Is A or B correct? Or are both considered Kernel matching? A (1) Estimate ...
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Regression with two sample groups

I hope you can help me with the following problem: I have two sample groups. From the first group I know the explanatory variable x (pre-status) and from the second group I know the variable y (post-...
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49 views

How to compare different causal inference methodologies for estimating Average Treatment Effect when true treatment effect is unknown?

I'm comparing various methods for estimating average treatment effects (ATEs) for cost savings in a case-control study on health insurance episode of care data for my employer. My company currently ...
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verifying pre-treatment trend assumption when there are multiple treatment time in Diff-in-Diff

One of my colleagues and I had a debate on Propensity Score Matching (PSM) + Diff-in-Diff (DD) when there are multiple time periods (some people called it staggered DD). Compared to the standard DD ...
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43 views

Match Adjusted Indirect Comparison with continuous and categorical variables [closed]

I am attempting to replicate the analysis here: http://nicedsu.org.uk/technical-support-documents/population-adjusted-indirect-comparisons-maic-and-stc/ (see appendix D). Specifically, the MAIC in ...
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58 views

How is a linear regression performed on exact matched data following $k:1$ matching?

I understand how regression is performed following exact matching on subclassification categories of data (for example, grouping individuals according to sex, age, etc.). Is regression on $k:1$ ...
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8 views

Multi feature matching

this might be a really intro question, But if I have two dataframes like: ...
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38 views

Setting the number of matches in Genetic Matching

I am using the GenMatch function from the Matching R-package to achieve a balance between the covariates in a treatment and control group. The GenMatch function allows to set M, which is according ...
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49 views

Is it possible of overfit using Propensity score matching with the MatchIt R package?

I have a very large patient cohort and I am trying to define cases and controls whilst minimizing selection bias. Further down the line, I am using Cox regression to assess the efficacy of particular ...
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Separate Matching Analyses for Heterogenous ATT Effects

I have three treatments, and I'm trying to calculate the ATTs. The literature in my field seems to deal with this one of two ways. The first way involves conducting separate matching procedures for ...
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31 views

match on a variable that itself depends on matching

I want to determine whether Program X improved graduation rates at a higher ed institution. Students self-select into this program, so I'm using propensity score matching (with the ...
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26 views

Is there a way to evaluate the accuracy or misclassification rate of the linear model that the R package MatchIt uses to build propensity scores? [closed]

m1.out <- matchit(Treatment ~ co_variate_1 + co_variate_2 + co_variate_3, data = mydata, method = "nearest", ratio = 1) summary(m1.out) I am ...
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67 views

Propensity Score Matching with Cox Regression

I am conducting a survival analysis with a Cox regression whereby the outcome variable (promotion to a senior role) is either 0 or 1. I am particulalry interested in the hazard rate (i.e., the 'hazard'...
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case-control matching with stratum of different length

I want to match cases with controls. My restriction is that a case must be assigned k controls. I use the notation $n:m$, being a stratum with $n$ cases and $m$ controls. For some cases I can ...
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Propensity score matching in r using panel data [closed]

I want to conduct PSM using firm panel data in r. matchit(treat ~ leverage + cash + roa + mtb + asset, data=data) This gave me a result of only very similar one ...
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45 views

Matching Before Randomization in R [closed]

I would like to divide 100 subjects into 50 matched pairs. Within each pair, I would like to randomize one subject into a treatment group and the other into a control group. I would like to match the ...
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308 views

advantages and disadvantages of IPTW vs propensity score matching?

what are the advantages and disadvantages of IPTW (Inverse Probability of Treatment Weighting) comparing to PSM (propensity score matching) in dealing with confounding variables?
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In an observational study where matching is properly conducted, should we expect the $ATE$ to be equal to the $ATT$?

In a randomized study, I know that the $ATE=ATT=ATC$, where $ATE$ is the average treatment effect, $ATT$ is the average treatment effect on the treated, and $ATC$ is the average treatment effect on ...
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78 views

Matching subjects with themselves when evaluating short term outcomes

I am considering a simple causal inference scenario; Let's say we want to examine the effect of paracetamol (treatment) on curing headache (outcome). When performing matching, is it okay to match ...
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Matching: strange p-value for Rosenbaum sensitivity test using rbounds package

I'm using R to conduct genetic matching (Matching package) and do Rosenbaum sensitivity tests to test the sensitivity of my ...
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2answers
30 views

Does rowwise distribution of random values in creating a normally distributed vector variable in matrix(rnorm(.), byrow=TRUE) damage normality?

(Reprodicible example added) 150-character-limitless full question is: Does the rowwise distribution of values in creating a normally distributed vector variable via ...
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57 views

What statistical test would I use to test that both data sources are matching [closed]

Suppose I am only working with two datasets, Data Source 1 with columns Customer ID and ...
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28 views

Is there a name for simple categorical matching / distance matching hybrid?

I have a cohort of individuals I need to match. I'm matching over age, gender, and location, but this isn't enough to get good results from just distance matching or propensity score matching. Is ...
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27 views

What does summary of the model (T-stat and p-values) after Matching using R's “Matching” package indicate?

I am using the GenMatch and Match functions in R's Matching package to balance covariates in an observational study via Genetic Matching. However, the documentation for this package does not describe ...
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63 views

How to data entry for a matched case control study

Please tell me how to enter my samples in excel can I first enter cases then controls in same sheet? What about match ID and group indicator?
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194 views

Exact matching + multiple regression on high-dimensional treatment-control study?

I'm working on a project with healthcare data where episodes of care in the treatment and control groups must be matched to estimate average treatment effect (ATE). I have several hundred covariates ...
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58 views

NcNemar's test for 1:2 matched data

Does anyone use McNemar's test for fractional values after 1-to-2 propensity score matching? How correct would it be? For instance, let me have 0-1 outcomes and the following matched observations (...
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417 views

Propensity scores in logistic regression models

I have a query after reading a paper, which is about the effectiveness of a medical device. In summary, what the authors did was 1. Generating a propensity score using a multivariable logistic ...
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1answer
47 views

Degrees of freedom in matching for calculating p-value of t-score

I am running a matching analysis using the Match function from the Matching R-package. My sample includes 86048 firms, from which 611 have received treatment. After matching on sector(exact), number ...
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Data matching technique

I have a database of different clients and I know from which countries these customers source their good from. E.g. XZY company sources 80% of the goods from China 10% from India and 10% from Russia. ...
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How to design inclusion criteria to match groups?

I am currently working on a study with a population of mostly veterans with chronic spinal cord injuries (goal n=60, currently n=27). We decided to add a comparison group of able-bodied controls that ...
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143 views

Propensity score matching with MatchIt: Question on missing standard mean differences in balance tab on cobalt package

I am using MatchIt to carry out some propensity score matching, and then using the cobalt package to generate the balance diagnostic. The summary() command on MatchIt has a known bug where it does not ...
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64 views

Why is Propensity Score called a distance measure as well?

I had to use Propensity score matching for my study. I used the MatchIt function in R and I studied what it actually does. I understand that the propensity score is calculated using Logistic ...
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37 views

In causal inference, is the usual unconfoundedness assumption interpreted to apply at the unit or covariate level?

Suppose for each unit $i \in \{1, \ldots, N\}$, we have that $(Y_i(1),Y_i(0))$ are the potential outcomes, $Z_i$ is the treatment, and $X_i$ the covariates. I have seen the following two ...
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If unconfoundedness holds under a set of covariates $X$, will it also hold on an extended set of covariates, $(X,X')$?

Suppose unconfoundedness holds for a set of potential outcomes $(Y(1),Y(0))$ and treatment $Z$, conditional on a set of covariates, $X$ such that: $$ (Y(1),Y(0)) \perp Z \mid X $$ Then, is it ...
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36 views

In Exact Matching in Causal Inference, why is it that that $P(X_i=x\mid Z_i = 1)= P(X_i=x\mid Z_i = 0)$ where $X,Z$ are the covariates and treatment?

In Exact Matching in Causal Inference, I read that because we assume exact matches, then exact balance occurs in the distribution of the covariates. It is then often stated that if $X,Z$ are the ...
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For Matching on a categorical variable with N categories, will it suffice to create (N-1) binary features and match on them?

I have data on patients who received different amounts of Occupational therapy (High Dose vs Low Dose) after a stroke. We are investigating if there are differences in recovery between patients from ...
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Estimating weights in the assignment problem

How would you learn a function with the emphasis on feature interactions? I have the standard assignment problem: $$ \max_{x_{ij}} \sum_{(i, j)} w_{ij} x_{ij}, $$ where $w_{ij}$ is the weight of ...
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194 views

How exactly to evaluate Treatment effect after Matching?

In Elizabeth's Stuart's 2010 paper "Matching methods for causal inference: A review and a look forward", she states the following: "Section 5: Analysis of the Outcome: ... After the matching has ...
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Best method to investigate treatment effect after creating a Matched control group using Gentic Matching (with replacement)?

Project background: I have data on patients who received varying amounts of therapy dose during treatment of stroke-induced paralysis. I wish to investigate if there are differences in motor-function ...
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459 views

Matching with Multiple Treatments

What's the best way to use matching methods with multiple treatment groups? I'm assessing the impact of an intervention on an outcome. For my first analysis, I used the MatchIt package (see code below)...
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1answer
181 views

is there a way to find suitable ratio for matches to controls (using “ratio” in Matchit package in R or other programs)

I am using matchit package in R to find a control set for my treated units and I am testing the model with different ratio to get suitable control set. Is there a way to find suitable ratio and I will ...
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29 views

Matching covariate selection- should we not match on binary features where overwhelming majority of subjects fall in one category?

I am trying to investigate if there is a relation between Occupational Therapy (OT) dosage for stroke patients and patient recovery. I have separated the patients into 2 groups by the amount of ...
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1answer
51 views

What type of regression for two groups of data?

I have data from 500 school children who took a test. 250 of the children have a certain type of disability (group A). Each child in group A was matched to a child on the basis of age, gender to a ...
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How to predict matching between two objects? [closed]

There is information from a website which connects questions from users to suitable professionals that might be interested in answering the particular questions. The data contains over 10.000 ...
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36 views

What distance function to use for matching observations on a mix of ordinal, nominal and numeric variables?

I'm trying to match potential respondents to a random sample from the target population, and not sure whether any of the usual methods available out-of-the-box in e.g. R are right for the job. ...