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From |
Harini Sarathy <harini.parth@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: RE: Survey and -catplot- |

Date |
Sat, 21 Jan 2012 11:57:21 -0500 |

Shaun, Thanks for responding. I am using the same weight I used for the svy analysis (I've sort of combined data from NHANES-III and the continuous NHANES, so I created a new sampling weight). While looking online for catplot help, I found someone suggesting that I should use 'aweight' instead of 'pweight'. Stata also gives an error if 'pweight' is used, so I guess 'aweight' is the correct usage for weight. I used the same sampling weight for aweight - frankly I don't know the difference and what it means, and I just sort of aped the example. Harini On Sat, Jan 21, 2012 at 11:48 AM, Scholes, Shaun <s.scholes@ucl.ac.uk> wrote: > Are you sure the weight specified in the catplot command was the same weight that was used in your svy commands? I have not analysed NHANES myself but I would expect to use a pweight rather than aweight? > Can you check this using svydes (I'm assuming this is individual level NHANES data)? > Best wishes > Shaun > > > > > -----Original Message----- > From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Nick Cox > Sent: 21 January 2012 15:58 > To: statalist@hsphsun2.harvard.edu > Subject: st: Survey and -catplot- > > Harini Sarathy <harini.parth@gmail.com> had difficulties sending this to the list. I will look at it shortly myself but anyone is naturally free to answer first. > > Nick > > I'm doing survey analysis with NHANES data from 1988-2008 and have been trying to use -catplot- (SSC) to show trends in abdominal obesity over the survey years (sddsrvyr) across age groups (agegrp): > > Abdominal obesity (abdobes) is a binary/discrete variable. (0 "Normal" > 1 "Abdominal Obesity" > > sddsrvyr > 1988-1996: 1 > 1999-2000: 2 > 2001-02 : 3 > 2003-04 : 4 > 2005-06: : 5 > 2006-07 : 6 > > For my analysis I created subpopulations for the age groups: sub_0812, sub_1317, sub_1840 (These subpopulations had complete data on variables of interest). > > The big picture: I have one binary variable (abdobes), two categorical variables (sub_0812/sub_1317/sub_1840 & sddsrvyr). I want to show the increasing trend in abdominal obesity over the survey years within each group - but I only want to show it for abdobes==1 > > Proportions of obesity > > . svy: prop abdobes, sub(sub_0812) over(sddsrvyr) . svy: prop abdobes, sub(sub_1317) over(sddsrvyr) . svy: prop abdobes, sub(sub_1840) over(sddsrvyr) > > sub_0812: Abd Obese==1 > > _sddsrvyr_1 .1099138 > _sddsrvyr_2 .1972264 > _sddsrvyr_3 .205952 > _sddsrvyr_4 .2562671 > _sddsrvyr_5 .2243748 > _sddsrvyr_6 .2589271 > > > sub_1318: Abd Obese==1 > > _sddsrvyr_1 .1288447 > _sddsrvyr_2 .1717575 > _sddsrvyr_3 .1773453 > _sddsrvyr_4 .2003957 > _sddsrvyr_5 .1790184 > _sddsrvyr_6 .2129547 > > > sub_1840: Abdo Obese==1 > > _sddsrvyr_1 .2576976 > _sddsrvyr_2 .3403194 > _sddsrvyr_3 .3599359 > _sddsrvyr_4 .3894223 > _sddsrvyr_5 .3934921 > _sddsrvyr_6 .394528 > > For the purposes of a graph, I created a variable sub_all to represent all age-groups > > gen sub_all=0 if sub_0812==1 > replace sub_all=1 if sub_1317==1 > replace sub_all=2 if sub_1840==1 > > The catplot command I used does not give me the graph I expected. Can you point out where I went wrong? > > > catplot sddsrvyr sub_all [aweight=wtmeccombined] if abdobes==1, > percent(sub_all) asyvars bar(1, bcolor(red)) bar(2, bcolor(midgreen)) bar(3, bcolor(sandb)) bar(4, bcolor(pink)) bar(5, bcolor(ebblue)) bar(6, bcolor(orange)) vertical title("Trends in Abdominal Obesity in NHANES population from 1988 to 2008 across age-groups", > size(medsmall)) ytitle(%) > > According to the graph, I'm putting down approximations here > > sub_0812: Abd Obese==1 > > _sddsrvyr_1 .18 > _sddsrvyr_2 .13 > _sddsrvyr_3 .165 > _sddsrvyr_4 .18 > _sddsrvyr_5 .17 > _sddsrvyr_6 .175 > > > sub_1318: Abd Obese==1 > > _sddsrvyr_1 .22 > _sddsrvyr_2 .135 > _sddsrvyr_3 .1475 > _sddsrvyr_4 .17 > _sddsrvyr_5 .165 > _sddsrvyr_6 .175 > > > sub_1840: Abdo Obese==1 > > _sddsrvyr_1 .25 > _sddsrvyr_2 .1475 > _sddsrvyr_3 .145 > _sddsrvyr_4 .15 > _sddsrvyr_5 .16 > _sddsrvyr_6 .15 > > Given the values from the analysis, I'd expect an increasing trend in each age group. e.g. In age group 18-40, I expected it go from 25.7% to 39.4 %, whereas the graph shows something different. > > I know the problem lies in creating the variable "sub_all"and it does not seem to capture the information for the individual age groups. > Does anyone have any ideas about what went wrong? And what is the way to correct it? > > * > * 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/

**Follow-Ups**:**RE: st: RE: Survey and -catplot-***From:*"Scholes, Shaun" <s.scholes@ucl.ac.uk>

**References**:**st: Survey and -catplot-***From:*Nick Cox <njcoxstata@gmail.com>

**st: RE: Survey and -catplot-***From:*"Scholes, Shaun" <s.scholes@ucl.ac.uk>

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