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From |
sjsamuels@gmail.com |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: SVY: tab with three variables |

Date |
Fri, 1 May 2009 13:04:42 -0400 |

I intended the -subpop- to account for randomness in the sizes of the two remaining subgroups, not to account for the fact that the third subgroup was ignore. I should have explained that the population size reported by Stata is the sum of the probability weights for the sample members. That is why I suspect that the weight variable is incorrect. -Steve On Fri, May 1, 2009 at 11:46 AM, Austin Nichols <austinnichols@gmail.com> wrote: > Adebola Odunlami <aodunlam@hsph.harvard.edu>: > > In re Steven's point (2): If one group is not asked the question, it > is not a big deal IMHO. Using subpop or not will give the same answer > when the variable is missing outside the subpop, in general. > > In re Steven's point (3): you might want the se or ci option in > addition to row option, so that the row proportions are saved in e(b) > and you can test hypotheses across rows, e.g. > > clear > webuse nhanes2 > svyset > svy: tab black diab, row ci > test _b[p22]=_b[p12] > svy, subpop(if age>59): tab black diab, row ci > test _b[p22]=_b[p12] > replace diab=. if age<=59 > svy: tab black diab, row ci > test _b[p22]=_b[p12] > > > On Fri, May 1, 2009 at 11:15 AM, <sjsamuels@gmail.com> wrote: >> Welcome to Stata! Reposting a question will not get it answered any >> faster. See the Stata FAQ about why questions do not get answered. >> In your case, your post is hard to read. Your questions are mixed up >> with snippets of Stata code, and other statements. >> >> Important! Something appears wrong with your survey set up. You have >> n = 5,191 observations, but Stata reports that the total population >> size is only N = 3,061, You could be using the wrong probability >> weight. Stop and fix this problem. >> >> To answer your questions. >> >> 1. If you have survey data, you must always -svyset- with the >> appropriate setting. Consult your advisor if you do not understand >> why, or look at Sharon Lohr, "Sampling, Design and Analysis", Duxbury >> Books. >> >> 2. Your new race-ethnicity variable seems okay. You can >> cross-tabulate it against the original variable to check. >> >> You have a potential problem if whites were not asked this question: >> the survey weights might give misleading results if applied to >> nonwhites alone. This is not an elementary matter and you should >> consult someone who is knowledgeable about surveys for advice. Bring >> the study documentation with you when you do this. >> >> 3. -svy: tab- with the tab() option doesn't do what you think it >> does. Read the -help- to see why. >> >> I'm assuming that the new race-thnic variable is recoded 1 & 2. >> >> svy, subpop(if racethn==1), tab sex psymps, row >> svy, subpop(if racethn==2), tab sex psymps, row >> >> -Steve >> >> On Fri, May 1, 2009 at 10:01 AM, Adebola Odunlami >> <aodunlam@hsph.harvard.edu> wrote: >>> Hi all, >>> >>> I was hoping someone would please address my question below. Any help/insight is greatly appreciated. >>> thanks in advance. >>> >>> I am relatively new to stata and I have a few related questions. I want to get proportion of units that answered a question( variable name = psysymps) by thier gender(sex) and race (race3cat) after I survey set the data. I tried "bysort race3cat: tab psysymps sex, row col chi2" but then realized the percentages were off and I needed to use svy commands. I then tried "svy: tab racet3cat sex, tab (psysymps) row se ci" but got a response that the table contains 0 in the marginals and therefore statsitics cannot be computed. I realized that one of the race categories (e.g. White) was not asked the question. So I created a new race category ("blackethn) that sets Whites to missing and others to either 1 or 2. Then I proceeded with my primary objective to see proportions of 'psysymps' by race and sex and tried "svy: tab blackethn sex, tab (psysymps) row se ci". This gave me the table below. >>> >>> My questions are: 1) must I always svy set before each code e.g svy: tab instead of just tab?; 2) was it okay to set Whites to missing as they were not asked this question and I dont want them counted as a denominator in my proportion?; 3) the table below still does not give me tabs of my variable by race and sex. how do I do this? Instead the table gave me---of those who answered yes to psysymps, what proportion of race/blackethn =1 were men and what prop were women? I would like to know how to code to get----what proportion of race/blackethn==1 men answered 'yes' to psysymps, compared to race/blackethn== 1 female (and also the proportion of race/blackethn ==2 men that answered yes to to psysymps, compared to race/blackethn== 2 female and associated chi2) >>> > > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/statalist/faq > * http://www.ats.ucla.edu/stat/stata/ > * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**References**:**st: SVY: tab with three variables***From:*"Adebola Odunlami" <aodunlam@hsph.harvard.edu>

**Re: st: SVY: tab with three variables***From:*sjsamuels@gmail.com

**Re: st: SVY: tab with three variables***From:*Austin Nichols <austinnichols@gmail.com>

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