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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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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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30 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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26 views

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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1answer
10 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. ...
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1answer
30 views

Estimation of average treatment effect based on nearest neighbor matching [closed]

I would like to use R to duplicate the treatment effect estimation method used in Stata. Specifically, this is the Stata method I would like to duplicate. I have tried the package ...
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1answer
29 views

After performing Matching with replacement, should tests (t-test/ KS test) to evaluate balance between the matched groups include repeated subjects?

I am using Genetic Matching to infer causality from observational data. Because I am matching with replacement, the matched Control group has multiple instances of some of the same subjects. In this ...
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6 views

Synthetic Controls vs Coarsened Exact Matching with weights vs Coarsened Exact Matching k2k

My question is mostly out of curiosity. How one should choose between synthetic controls and coarsened exact matching (CEM) when he/she wants to combine it with difference-in-difference design? ...
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1answer
28 views

In matching procedures in causal inference, will matching on more covariates always decrease the bias? Can the bias ever increase? [duplicate]

There are various matching procedures in the causal inference literature, from exact matching to propensity score matching and more. The goal is usually to find the Average Treatment Effect (ATE). ...
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19 views

Is matching necessary for prediction from logistic regression?

I have a data set with very imbalanced groups (about 3% have an effect, while 97% don't). I experimented with logistic regression and was convinced that I can get to a very good accuracy of prediction ...
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1answer
38 views

A difference-in-differences propensity score matching approach

I am facing some challenges using the DID.I have around 500 Items off which 100 are test and its very difficult to find a control group for DID, so I used PSM to find control group using nearest ...
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18 views

Propensity score matching and DD over different event windows

I'm currently working on a project in which we are trying to investigate the operating (accounting) performance of seasoned equity offerings. To comprehend the endogeneity problem, we apply ...
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5 views

How to match different samples with different tests in a structural equations model? SPSS / AMOS

I am working on a study on hotels that analyzes the possible influence of the labor sastifacción (MSQ, 20 questions scale 1 to 5) in customer satisfaction (scale 1 to 5, questions that evaluate ...
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1answer
88 views

what's the difference between stratified sampling and matching?

I am trying to find a good technique to balance data in which the minority class is about 1% of the data. As I understood, the most common practice is matching. What is the difference, though, ...
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25 views

SMOTE algorithm gives better AUC than matching

I have a highly imbalanced data set: a total of 13000 patients, 160 having condition A, and various other features which could be predictors. In order to balance the data I did two things: 1) ...
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24 views

Difference in means test for coefficients from two matching models

I have a model estimating the effect of a treatment on two different populations, and a theoretical hypothesis that the effect should be larger for population A than for population B. I can address ...
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1answer
74 views

Is it correct to use paired t test after 1:2 matching?

Is it correct to use paired t test after 1:2 propensity score matching? How we can do this in R? I found the following link in SPSS (https://www.researchgate.net/post/how_is_paired_t-...
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8 views

Compute Sensitivity and Specificity with Incomplete Data

I have two data sets $A$ and $B$ which I want to combine using statistical methods (e.g. some matching algorithms such as Nearest Neighbor). I have a third data set $C$ that encompasses the true ...
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1answer
21 views

R- Trouble understanding what loss function is being used by Genmatch (genetic matching) algorithm

I am having some trouble understanding what loss function is being minimized to ensure that we are converging towards the best set of weights in the Genmatch function in R. I was reading the paper on ...
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23 views

Matched case control data

I'm new to working with matched case-control data. I have a study where case individuals are matched to controls in a 1:3 way. This means that for every case (diseased) I have three matched controls (...
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16 views

R- trouble understanding how setting estimand to “ATE” is affecting matching in “Matching” package

I am working on a project where I am using observational data from patients and trying to find a causal relationship on how Treatment dose affects Patient recovery. Since the data is observational, I ...
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“Matching” groups in a clinical study

I have the following question regarding a clinical study in the Surgery department of an hospital: 1) I have two groups of patients: group A - comprising patients operated in 2016; group B - ...
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1answer
174 views

How to do PSM with panel data using PanelMatch?

I would greatly appreciate if you could let me know how to use PanelMatch for my dataset. Unfortunately, I couldn't find it's manual so I don't know how to find which firms are matched, how to extract ...
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1answer
28 views

Do propensity score matching methods need to factor in the index date in a matched cohort context?

I am working on a comparative effectiveness study where we estimated the propensity of treatment between two groups and are exploring matching on the propensity score. The study period is long, ...
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How to understand “controls” in matching versus regression

I'm trying to understand matching in comparison to regression, especially how using 'controls' in regression changes in matching. The part I don't understand is about the distribution of covariates ...
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1answer
168 views

1:1 nearest neighbor propensity score matching in R (MatchIt package)

I used 1:1 nearest neighbor propensity score matching in R (MatchIt package) to match samples from an experimental group with a control sample. I used the procedure described here: https://pareonline....
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1answer
39 views

Propensity score matching: covariate balance

I have one concern about propensity score matching's assumption. It seems that what propensity score is doing is to say that the choice of treatment depends on pre-treatment covariates. Suppose I am ...
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1answer
174 views

Matching on pre-treatment outcome in diff-in-diff

The parallel trends assumption for a difference-in-differences analysis does not require the level of the trends to be similar (just parallel). However, in a case where we want the levels to be ...
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1answer
70 views

Diff-in-diff with mactched control group

I want to run a diff-in-diff model. To choose an appropriate control group, I use a nearest-neighbor matching model based on several determinants of the outcome variable that I study. I was ...
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1answer
33 views

In propensity score matching, what violations or implications may result from having fitted propensity scores that are not centered at 0.5?

I currently have a procedure doing propensity score matching, and I use the fitted propensity scores (obtained via a glm call) and match on those. It turns out that I have about 60-70% more fitted ...
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16 views

Variable ratio matching

I am working on a simulated study where I have variable number of control matches for my treatment subjects. I am new to this type of analysis. I realize after matching I can utilize logistic ...
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0answers
132 views

Conditional logistic regression on matched data with replacement

I'm using 1 to 5 matching on my data with replacement, where each treatment is paired to at most 5 control units with the possibility of one control unit being assigned to more than one treatment. ...
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0answers
20 views

compare single value to a sample

I wish to compare a single case (i.e. 100% of a population of 1) to a sample of another population. I am accustomed to using standardized differences for both dichotomous and continuous variables ...
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33 views

How does the “BiasAdjust” term in Match() function from Matching R package work?

In the Match() function in the Matching R package, it takes in inputs like: ...
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1answer
19 views

Evaluating propensity score matches- what to do when ratio of variances or standardized means of difference go to infinity?

I am working on a project where I am comparing the effects of a particular treatment on patients with other patients who didn't receive the treatment. As I am trying to replicate a randomized ...
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1answer
43 views

For the Match() function in the R package, “Matching”, what algorithm is used for propensity score matching?

In the Matching package in R, one can conduct propensity score matching if propensity scores are passed to the ...
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1answer
54 views

What is the purpose of using MatchIt in R with nearest neighbors for estimation of ATE if it does not report which pairs are matched?

I am currently using the matchit function in MatchIt in R. For example, in the call: ...
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1answer
176 views

MatchIt: Explanation of Missing Factors from Summary

I am using the MatchIt package to perform matching between two groups (obese and not obese). The dataset that I am using has no missing data. I am matching on age, sex, and race. Sex and race are ...
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1answer
571 views

3:1 matching with MatchIt in R. The number of matched control is not equal to 3 times the number of cases

Hello I'm using the MatchIt package in R I have a total of unmatched 116 treated cases and 462 unmatcehd non-treated case with the command ...
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1answer
29 views

Accounting for “surgeon preference” when modeling a binary surgical outcome

I'm trying to model the risk of a binary event following surgery (event=admitted for observation, y/n), and my main predictor is a three-level 'treatment' administered during the procedure (Tx_A, Tx_B,...
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68 views

Confidence intervals after one-to-many matching - number of degrees of freedom

I have propensity score matched data after 1-to-3 matching. I am trying to use the code from the answer to https://stackoverflow.com/questions/37973240/ The question is: what number of degrees of ...
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116 views

Paired tests for one-to-many matched observations

I have a propensity score matched data after 1-to-2 matching. Each treatment case is matched to one or two control cases. May I use paired tests to compare the outcomes? The discussion https://www....
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27 views

Evaluating Impact of Unobserved Confounders - Is the E-Value applicable for Non-Significant Group Differences?

I have conducted an analysis of treatment effects based on observational data (via statistical matching). As suggested by VanderWeele and Ding (2017), I want to evaluate the sensitivity of my analysis ...
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57 views

Matching: is here an equivalent for caliper with mahalanobis model (as in logit model)

I'm trying to set the caliper value to a matching with mahalanobis metric method in R. Although a smaller value effectively improves the model (and decreases the number of matched items as a tradeoff) ...
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44 views

Difference-in-Difference with multiple regression vs. matching combined with Difference in Difference

I want to use a Difference-in-Difference approach. In order to make sure treatment and control group are similar, I want to use a propensity score matching before the DiD approach. What I do is to ...
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1answer
41 views

Interacting treatment variables with independent variables in matched samples

Can we interact the treatment variables with independent control variables that have been used for matching? I have a binary treatment variable called 'medicine'. It indicates whether a person ...
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0answers
20 views

Modeling hip fracture incidence (hospital-based cohort design)

Hoping someone can help me out with a question I have on an analysis looking at prosthetic hip fracture incidence following hip replacement surgery (exposure=type of implant, with reference being the ...
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1answer
240 views

Using propensity score AND exact matching for control group selection

I am working with a team of researchers looking to select a control group out of a large population (150,000) to compare with a relatively small treated group (~900). We plan on using a propensity ...
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2answers
385 views

In propensity score matching, should a variable used in exact matching also be used in the model?

In propensity score matching, we can match on variables exactly. For example, we can match males with other males only. Additionally, the variable can be specified in the model. Here's some SAS code ...
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32 views

How to handle bias due to self-selection in one group

I want to compare two or three social groups across a set of dependent variables, using data from a longitudinal survey. The problem is that membership in one of the groups leads to a self-selection ...
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23 views

Appropriate statistical test after matching pairs

I am working on a project where I have twitter user profiles and their tweets. The users are divided based on their number of followers in two groups (g1 and ...