Hi Austin,
Thanks for your prompt reply. I have selected the records as per my
inclusion - exclusion criteria. Hence, my data does not contain whole
NIS database.
Regards,
Mihir
On Wed, Sep 30, 2009 at 1:42 AM, Austin Nichols <[email protected]> wrote:
> Mihir <[email protected]> :
> I sincerely doubt you have 60 strata over all 10 years; you may need
> http://www.hcup-us.ahrq.gov/db/nation/nis/nistrends.jsp
> or an equivalent.
>
> On Tue, Sep 29, 2009 at 1:29 PM, Mihir <[email protected]> wrote:
>> Dear all:
>>
>> I am stuck with a problem in pearson chi-square test with survey
>> command. I have setup survey setting for Nationwide Inpatient Survey
>> (NIS) data. I used hospital id as sampling unit, discwt as sampling
>> weight and stratum variable as strata as suggested on NIS website.
>> When I am trying to run chi-square test for independence between age
>> category and year of data collection from 1998 to 2007, it gives
>> proper result, but when I run the same command by retaining only two
>> years (1998 and 2007), it does not produce p-value. I don't understand
>> why it is happening? Can anybody help me - what I should do? I am also
>> getting similar results with other variables that same command works
>> with more year but doesn't work with two years.
>>
>> I have pasted my output for your ready reference.
>>
>> Thanking you in advance,
>> Mihir
>>
>> svyset hospid [pweight=discwt], strata(stratum) vce(linearized)
>>
>> pweight: discwt
>> VCE: linearized
>> Strata 1: stratum
>> SU 1: hospid
>> FPC 1: <zero>
>>
>> svy: tabulate year age2cat, count column row obs percent format(%10.0g) pearson
>> (running tabulate on estimation sample)
>>
>> Number of strata = 60 Number of obs = 157222
>> Number of PSUs = 3270 Population size = 759816.12
>> Design df = 3210
>
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