Re: st: propensity score matching question

[Nyasha Tirivayi <ntirivayi@gmail.com>]

Dear Peter

Thanks for your response. The study is evaluating the impact of food
aid on adherence to medication. The hypotheses is that food aid
improves adherence to medication. I have three groups of the treated
i.e.  first group was on food aid from july 2009 to dec 2009, second
group from may 2009 to Jan 2010  and third group from december 2009 to
July 2010. The first group has about 36 people, the second around 65
and the last one abour over a 100.

The comparison group has over 1000 people. Since I do not have the
same baseline for everyone, is propensity score matching still ideal
for my evaluation? How would I account for the varying times in
program participation by the three treated group?   If not, what other
method can I use in Stata.

Kindly advise

Regards

N. Tirivayi
Maastricht
Netherlands



On 6/20/12, TA Stat <tastat@gmail.com> wrote:
> Additional information, particularly your research questions and
> hypotheses, is needed. PS matching is for balancing measured
> covariates among groups being compared.
>
> Peter
>
> On Wed, Jun 20, 2012 at 9:48 PM, Nyasha Tirivayi <ntirivayi@gmail.com>
> wrote:
>> Hello
>>
>> I am trying to do an impact evaluation of a social program. I am doing
>> this retrospectively. However I have just found out that the
>> beneficiaries have different baselines and end dates i.e. they got
>> into the program at different times and exited at different times.
>> Since I do not have the same baseline for everyone, is propensity
>> score matching still ideal for my evaluation? How would I account for
>> the varying times in program participation?   If not, what other
>> method can I use in Stata?
>>
>> Kindly advise
>>
>> Regards
>>
>> N. Tirivayi
>> Maastricht
>> Netherlands
>>
>> *
>> *   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/
>

*
*   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/