___ ____ ____ ____ ____ tm /__ / ____/ / ____/ ___/ / /___/ / /___/ 9.2 Copyright 1984-2006 Statistics/Data Analysis StataCorp 4905 Lakeway Drive Special Edition College Station, Texas 77845 USA 800-STATA-PC http://www.stata.com 979-696-4600 stata@stata.com 979-696-4601 (fax) 6-user Stata for Linux (network) perpetual license: Serial number: 81290527962 Licensed to: Research Unit of General Practice, SDU Odense, Denmark Notes: 1. (-m# option or -set memory-) 15.62 MB allocated to data 2. (-v# option or -set maxvar-) 5000 maximum variables 3. Command line editing disabled 4. Stata running in batch mode Note: Your site can add messages to the introduction by editing the file stata.msg in the directory where Stata is installed. . do lbw1_analysis.do . * do ~/Teaching/GetStart_stata/Version2/Program/lbw1_analysis.do . . * Erstat flg linie med det directory som du gerne vil arbejde i . cd ~/Teaching/GetStart_stata/Version2/Program /home/stovring/Teaching/GetStart_stata/Version2/Program . . clear . set mo off . . * Erstat med navnet på den fil, hvor du har datasættet liggende . use ../../ISHR_dat/ishr/lbw1.dta (Hosmer & Lemeshow data) . . * Basal info om dato . d, d Contains data from ../../ISHR_dat/ishr/lbw1.dta obs: 189 (max= 744,725) Hosmer & Lemeshow data vars: 11 (max= 5,000) 2 Apr 2005 21:10 width: 14 (max= 60,000) size: 3,402 (max= 16,383,992) ------------------------------------------------------------------------------- storage display value variable name type format label variable label ------------------------------------------------------------------------------- id int %8.0g identification code low byte %8.0g yesno birth weight<2500g age byte %8.0g age of mother lwt int %8.0g weight at last menstrual period race byte %8.0g race race smoke byte %8.0g yesno smoked during pregnancy ptl byte %8.0g premature labor history (count) ht byte %8.0g yesno has history of hypertension ui byte %8.0g yesno presence, uterine irritability ftv byte %8.0g number of visits to physician during 1st trimester bwt int %8.0g birth weight (grams) ------------------------------------------------------------------------------- Sorted by: . . ********************************************************************** . * 2x2 tabel på sammenhæng mellem rygning og risiko for lav fødselsvægt . ********************************************************************** . . tab low smoke birth | smoked during weight<250 | pregnancy 0g | 0. No 1. Yes | Total -----------+----------------------+---------- 0. No | 86 44 | 130 1. Yes | 29 30 | 59 -----------+----------------------+---------- Total | 115 74 | 189 . tab low smoke, row +----------------+ | Key | |----------------| | frequency | | row percentage | +----------------+ birth | smoked during weight<250 | pregnancy 0g | 0. No 1. Yes | Total -----------+----------------------+---------- 0. No | 86 44 | 130 | 66.15 33.85 | 100.00 -----------+----------------------+---------- 1. Yes | 29 30 | 59 | 49.15 50.85 | 100.00 -----------+----------------------+---------- Total | 115 74 | 189 | 60.85 39.15 | 100.00 . . * Risk, RR (tværsnitsstudie) . . cs low smoke | smoked during pregnancy| | Exposed Unexposed | Total -----------------+------------------------+------------ Cases | 30 29 | 59 Noncases | 44 86 | 130 -----------------+------------------------+------------ Total | 74 115 | 189 | | Risk | .4054054 .2521739 | .3121693 | | | Point estimate | [95% Conf. Interval] |------------------------+------------------------ Risk difference | .1532315 | .0160718 .2903912 Risk ratio | 1.607642 | 1.057812 2.443262 Attr. frac. ex. | .377971 | .0546528 .5907112 Attr. frac. pop | .1921887 | +------------------------------------------------- chi2(1) = 4.92 Pr>chi2 = 0.0265 . . * OR (opfattet som case-control eller i sin egen ret) . . cc low smoke Proportion | Exposed Unexposed | Total Exposed -----------------+------------------------+------------------------ Cases | 30 29 | 59 0.5085 Controls | 44 86 | 130 0.3385 -----------------+------------------------+------------------------ Total | 74 115 | 189 0.3915 | | | Point estimate | [95% Conf. Interval] |------------------------+------------------------ Odds ratio | 2.021944 | 1.029092 3.965864 (exact) Attr. frac. ex. | .5054264 | .0282695 .7478481 (exact) Attr. frac. pop | .2569965 | +------------------------------------------------- chi2(1) = 4.92 Pr>chi2 = 0.0265 . . * Variabel med alderskategorier . . recode age (0/19 = 1) (20/24 = 2) (25/29 = 3) (30/50 = 4), gen(agecat) (189 differences between age and agecat) . . la var agecat "Mothers age (categorized)" . la de agelab 1 "-19yrs" 2 "20-24yrs" 3 "25-29yrs" 4 "30+yrs" . la val agecat agelab . . sc age agecat, jitter(5) . . * 2x2 tabel med OR for hver alderskategori . . cc low smoke if agecat == 1 Proportion | Exposed Unexposed | Total Exposed -----------------+------------------------+------------------------ Cases | 7 8 | 15 0.4667 Controls | 16 20 | 36 0.4444 -----------------+------------------------+------------------------ Total | 23 28 | 51 0.4510 | | | Point estimate | [95% Conf. Interval] |------------------------+------------------------ Odds ratio | 1.09375 | .2719158 4.315057 (exact) Attr. frac. ex. | .0857143 | -2.677609 .7682534 (exact) Attr. frac. pop | .04 | +------------------------------------------------- chi2(1) = 0.02 Pr>chi2 = 0.8845 . cc low smoke if agecat == 2 Proportion | Exposed Unexposed | Total Exposed -----------------+------------------------+------------------------ Cases | 14 11 | 25 0.5600 Controls | 11 33 | 44 0.2500 -----------------+------------------------+------------------------ Total | 25 44 | 69 0.3623 | | | Point estimate | [95% Conf. Interval] |------------------------+------------------------ Odds ratio | 3.818182 | 1.191951 12.3363 (exact) Attr. frac. ex. | .7380952 | .161039 .9189384 (exact) Attr. frac. pop | .4133333 | +------------------------------------------------- chi2(1) = 6.63 Pr>chi2 = 0.0100 . cc low smoke if agecat == 3 Proportion | Exposed Unexposed | Total Exposed -----------------+------------------------+------------------------ Cases | 5 10 | 15 0.3333 Controls | 11 16 | 27 0.4074 -----------------+------------------------+------------------------ Total | 16 26 | 42 0.3810 | | | Point estimate | [95% Conf. Interval] |------------------------+------------------------ Odds ratio | .7272727 | .1518323 3.212992 (exact) Prev. frac. ex. | .2727273 | -2.212992 .8481677 (exact) Prev. frac. pop | .1111111 | +------------------------------------------------- chi2(1) = 0.22 Pr>chi2 = 0.6357 . cc low smoke if agecat == 4 | smoked during pregnancy| Proportion | Exposed Unexposed | Total Exposed -----------------+------------------------+------------------------ Cases | 4 0 | 4 1.0000 Controls | 6 17 | 23 0.2609 -----------------+------------------------+------------------------ Total | 10 17 | 27 0.3704 | | | Point estimate | [95% Conf. Interval] |------------------------+------------------------ Odds ratio | . | 2.425798 . (Cornfield) Attr. frac. ex. | . | .5877645 . (Cornfield) Attr. frac. pop | . | +------------------------------------------------- chi2(1) = 7.98 Pr>chi2 = 0.0047 Note: exact confidence levels not possible with zero count cells . . * Eller det samme med et "loop" . . forv i = 1/4 { 2. cc low smoke if agecat == `i' 3. } Proportion | Exposed Unexposed | Total Exposed -----------------+------------------------+------------------------ Cases | 7 8 | 15 0.4667 Controls | 16 20 | 36 0.4444 -----------------+------------------------+------------------------ Total | 23 28 | 51 0.4510 | | | Point estimate | [95% Conf. Interval] |------------------------+------------------------ Odds ratio | 1.09375 | .2719158 4.315057 (exact) Attr. frac. ex. | .0857143 | -2.677609 .7682534 (exact) Attr. frac. pop | .04 | +------------------------------------------------- chi2(1) = 0.02 Pr>chi2 = 0.8845 Proportion | Exposed Unexposed | Total Exposed -----------------+------------------------+------------------------ Cases | 14 11 | 25 0.5600 Controls | 11 33 | 44 0.2500 -----------------+------------------------+------------------------ Total | 25 44 | 69 0.3623 | | | Point estimate | [95% Conf. Interval] |------------------------+------------------------ Odds ratio | 3.818182 | 1.191951 12.3363 (exact) Attr. frac. ex. | .7380952 | .161039 .9189384 (exact) Attr. frac. pop | .4133333 | +------------------------------------------------- chi2(1) = 6.63 Pr>chi2 = 0.0100 Proportion | Exposed Unexposed | Total Exposed -----------------+------------------------+------------------------ Cases | 5 10 | 15 0.3333 Controls | 11 16 | 27 0.4074 -----------------+------------------------+------------------------ Total | 16 26 | 42 0.3810 | | | Point estimate | [95% Conf. Interval] |------------------------+------------------------ Odds ratio | .7272727 | .1518323 3.212992 (exact) Prev. frac. ex. | .2727273 | -2.212992 .8481677 (exact) Prev. frac. pop | .1111111 | +------------------------------------------------- chi2(1) = 0.22 Pr>chi2 = 0.6357 | smoked during pregnancy| Proportion | Exposed Unexposed | Total Exposed -----------------+------------------------+------------------------ Cases | 4 0 | 4 1.0000 Controls | 6 17 | 23 0.2609 -----------------+------------------------+------------------------ Total | 10 17 | 27 0.3704 | | | Point estimate | [95% Conf. Interval] |------------------------+------------------------ Odds ratio | . | 2.425798 . (Cornfield) Attr. frac. ex. | . | .5877645 . (Cornfield) Attr. frac. pop | . | +------------------------------------------------- chi2(1) = 7.98 Pr>chi2 = 0.0047 Note: exact confidence levels not possible with zero count cells . . * Sidste aldersgruppe (grp 4) er for lille - tilføjer den til grp 3 . . recode agecat (4 = 3) (agecat: 27 changes made) . . * Ændrer label - Bemærk: skal ikke igen "klistre" den på variabel med . * -label val- . . la de agelab 3 "25+yrs" 4 " ", modify . codebook agecat ------------------------------------------------------------------------------- agecat Mothers age (categorized) ------------------------------------------------------------------------------- type: numeric (byte) label: agelab range: [1,3] units: 1 unique values: 3 missing .: 0/189 tabulation: Freq. Numeric Label 51 1 -19yrs 69 2 20-24yrs 69 3 25+yrs . . sc age agecat, jitter(5) . . forv i = 1/3 { 2. cc low smoke if agecat == `i' 3. } Proportion | Exposed Unexposed | Total Exposed -----------------+------------------------+------------------------ Cases | 7 8 | 15 0.4667 Controls | 16 20 | 36 0.4444 -----------------+------------------------+------------------------ Total | 23 28 | 51 0.4510 | | | Point estimate | [95% Conf. Interval] |------------------------+------------------------ Odds ratio | 1.09375 | .2719158 4.315057 (exact) Attr. frac. ex. | .0857143 | -2.677609 .7682534 (exact) Attr. frac. pop | .04 | +------------------------------------------------- chi2(1) = 0.02 Pr>chi2 = 0.8845 Proportion | Exposed Unexposed | Total Exposed -----------------+------------------------+------------------------ Cases | 14 11 | 25 0.5600 Controls | 11 33 | 44 0.2500 -----------------+------------------------+------------------------ Total | 25 44 | 69 0.3623 | | | Point estimate | [95% Conf. Interval] |------------------------+------------------------ Odds ratio | 3.818182 | 1.191951 12.3363 (exact) Attr. frac. ex. | .7380952 | .161039 .9189384 (exact) Attr. frac. pop | .4133333 | +------------------------------------------------- chi2(1) = 6.63 Pr>chi2 = 0.0100 Proportion | Exposed Unexposed | Total Exposed -----------------+------------------------+------------------------ Cases | 9 10 | 19 0.4737 Controls | 17 33 | 50 0.3400 -----------------+------------------------+------------------------ Total | 26 43 | 69 0.3768 | | | Point estimate | [95% Conf. Interval] |------------------------+------------------------ Odds ratio | 1.747059 | .5152147 5.825634 (exact) Attr. frac. ex. | .4276094 | -.9409386 .8283449 (exact) Attr. frac. pop | .2025518 | +------------------------------------------------- chi2(1) = 1.05 Pr>chi2 = 0.3060 . . * Mantel-Haentzel analyse med test for homogenitet af OR . . mhodds low smoke, by(agecat) Maximum likelihood estimate of the odds ratio Comparing smoke==1 vs. smoke==0 by agecat ------------------------------------------------------------------------------- agecat | Odds Ratio chi2(1) P>chi2 [95% Conf. Interval] ----------+-------------------------------------------------------------------- -19yrs | 1.093750 0.02 0.8856 0.32257 3.70863 20-24yrs | 3.818182 6.53 0.0106 1.26362 11.53706 25+yrs | 1.747059 1.03 0.3095 0.58732 5.19685 ------------------------------------------------------------------------------- Mantel-Haenszel estimate controlling for agecat ---------------------------------------------------------------- Odds Ratio chi2(1) P>chi2 [95% Conf. Interval] ---------------------------------------------------------------- 2.043214 5.08 0.0242 1.083256 3.853864 ---------------------------------------------------------------- Test of homogeneity of ORs (approx): chi2(2) = 2.39 Pr>chi2 = 0.3031 . . . ********************************************************************** . * Analyse af fødselsvægt . ********************************************************************** . . * Stem-and-leaf "graf" . . stem bwt Stem-and-leaf plot for bwt (birth weight (grams)) 7** | 09 8** | 9** | 10** | 21 11** | 35 12** | 13** | 30 14** | 74 15** | 88,88 16** | 17** | 01,29,90 18** | 18,85,93,99 19** | 28,28,28,36,70 20** | 55,55,82,84,84 21** | 00,25,26,87,87 22** | 11,25,40,40,82,96,96 23** | 01,25,53,53,67,81,81,81,95 24** | 10,10,14,24,38,42,50,66,66,66,95,95,95,95 25** | 23,51,57,94 26** | 00,22,37,37,63,65 27** | 22,33,50,50,69,69,78,82 28** | 07,21,35,35,36,63,77,77 29** | 06,20,20,20,20,22,48,48,77,77,77,77 30** | 05,33,42,62,62,62,76,76,80,90,90,90 31** | 00,04,32,47,75,75 32** | 03,03,03,25,25,32,32,34,60,74,74 33** | 03,17,17,17,21,31,74,74 34** | 02,16,30,44,59,60,73,75,87 35** | 44,72,72,86 36** | 00,14,14,29,29,37,43,51,51,51,51,99 37** | 28,56,70,70,70,90,99 38** | 27,56,60,60,84,84 39** | 12,40,41,41,69,83,97,97 40** | 54,54 41** | 11,53,67,74 42** | 38 43** | 44** | 45** | 93 46** | 47** | 48** | 49** | 90 . bys smoke: stem bwt ------------------------------------------------------------------------------- -> smoke = 0. No Stem-and-leaf plot for bwt (birth weight (grams)) 1*** | 021 1*** | 330 1*** | 474,588,588 1*** | 701,729 1*** | 893,899,928,970 2*** | 055,055,082,100,187 2*** | 240,240,282,301,325,353,381,395 2*** | 438,442,450,495,495,523,551 2*** | 622,637,637,722,733,750,750,778 2*** | 807,835,835,836,863,877,877,920,920,920,977,977 3*** | 062,062,062,080,090,090,100,104,175,175 3*** | 203,203,225,225,232,232,234,274,274,317,317,374 3*** | 402,416,459,460,473,475,487,544,572,586 3*** | 600,614,614,629,651,651,699,728,770,770,770,790,799 3*** | 827,860,860,884,912,941,941,969,983,997,997 4*** | 054,054,111,153,167,174 4*** | 4*** | 593 4*** | 4*** | 990 ------------------------------------------------------------------------------- -> smoke = 1. Yes Stem-and-leaf plot for bwt (birth weight (grams)) 0*** | 709 0*** | 1*** | 135 1*** | 1*** | 1*** | 790 1*** | 818,885,928,928,936 2*** | 084,084,125,126,187 2*** | 211,225,296,296,353,367,381,381 2*** | 410,410,414,424,466,466,466,495,495,557,594 2*** | 600,663,665,769,769,782 2*** | 821,906,920,922,948,948,977,977 3*** | 005,033,042,076,076,090,132,147 3*** | 203,260,303,317,321,331,374 3*** | 430,444,572 3*** | 629,637,643,651,651,756 3*** | 856,884,940 4*** | 4*** | 238 . . * Normalfordelt? . . hist bwt, by(smoke) norm . qnorm bwt if smoke == 0 . qnorm bwt if smoke == 1 . . * Ens varians . . sdtest bwt, by(smoke) Variance ratio test ------------------------------------------------------------------------------ Group | Obs Mean Std. Err. Std. Dev. [95% Conf. Interval] ---------+-------------------------------------------------------------------- 0. No | 115 3054.957 70.1625 752.409 2915.965 3193.948 1. Yes | 74 2772.297 76.70106 659.8075 2619.432 2925.162 ---------+-------------------------------------------------------------------- combined | 189 2944.286 53.02811 729.016 2839.679 3048.892 ------------------------------------------------------------------------------ ratio = sd(0. No) / sd(1. Yes) f = 1.3004 Ho: ratio = 1 degrees of freedom = 114, 73 Ha: ratio < 1 Ha: ratio != 1 Ha: ratio > 1 Pr(F < f) = 0.8862 2*Pr(F > f) = 0.2275 Pr(F > f) = 0.1138 . . * Ens middelværdi . . ttest bwt, by(smoke) Two-sample t test with equal variances ------------------------------------------------------------------------------ Group | Obs Mean Std. Err. Std. Dev. [95% Conf. Interval] ---------+-------------------------------------------------------------------- 0. No | 115 3054.957 70.1625 752.409 2915.965 3193.948 1. Yes | 74 2772.297 76.70106 659.8075 2619.432 2925.162 ---------+-------------------------------------------------------------------- combined | 189 2944.286 53.02811 729.016 2839.679 3048.892 ---------+-------------------------------------------------------------------- diff | 282.6592 106.9544 71.66693 493.6515 ------------------------------------------------------------------------------ diff = mean(0. No) - mean(1. Yes) t = 2.6428 Ho: diff = 0 degrees of freedom = 187 Ha: diff < 0 Ha: diff != 0 Ha: diff > 0 Pr(T < t) = 0.9955 Pr(|T| > |t|) = 0.0089 Pr(T > t) = 0.0045 . . * Stratificeret på aldersgrupper . . bys agecat: ttest bwt, by(smoke) ------------------------------------------------------------------------------- -> agecat = -19yrs Two-sample t test with equal variances ------------------------------------------------------------------------------ Group | Obs Mean Std. Err. Std. Dev. [95% Conf. Interval] ---------+-------------------------------------------------------------------- 0. No | 28 2951.429 108.5356 574.3165 2728.732 3174.125 1. Yes | 23 3001.652 139.3161 668.1366 2712.728 3290.576 ---------+-------------------------------------------------------------------- combined | 51 2974.078 85.76863 612.5106 2801.807 3146.35 ---------+-------------------------------------------------------------------- diff | -50.2236 173.9697 -399.8289 299.3816 ------------------------------------------------------------------------------ diff = mean(0. No) - mean(1. Yes) t = -0.2887 Ho: diff = 0 degrees of freedom = 49 Ha: diff < 0 Ha: diff != 0 Ha: diff > 0 Pr(T < t) = 0.3870 Pr(|T| > |t|) = 0.7740 Pr(T > t) = 0.6130 ------------------------------------------------------------------------------- -> agecat = 20-24yrs Two-sample t test with equal variances ------------------------------------------------------------------------------ Group | Obs Mean Std. Err. Std. Dev. [95% Conf. Interval] ---------+-------------------------------------------------------------------- 0. No | 44 3080.75 109.9837 729.5496 2858.947 3302.553 1. Yes | 25 2641 109.1356 545.6779 2415.755 2866.245 ---------+-------------------------------------------------------------------- combined | 69 2921.42 84.01129 697.8502 2753.778 3089.062 ---------+-------------------------------------------------------------------- diff | 439.75 167.6828 105.0537 774.4463 ------------------------------------------------------------------------------ diff = mean(0. No) - mean(1. Yes) t = 2.6225 Ho: diff = 0 degrees of freedom = 67 Ha: diff < 0 Ha: diff != 0 Ha: diff > 0 Pr(T < t) = 0.9946 Pr(|T| > |t|) = 0.0108 Pr(T > t) = 0.0054 ------------------------------------------------------------------------------- -> agecat = 25+yrs Two-sample t test with equal variances ------------------------------------------------------------------------------ Group | Obs Mean Std. Err. Std. Dev. [95% Conf. Interval] ---------+-------------------------------------------------------------------- 0. No | 43 3095.977 133.8248 877.5476 2825.907 3366.046 1. Yes | 26 2695.654 141.5267 721.6474 2404.174 2987.134 ---------+-------------------------------------------------------------------- combined | 69 2945.13 101.102 839.8161 2743.385 3146.876 ---------+-------------------------------------------------------------------- diff | 400.3229 204.4174 -7.695911 808.3417 ------------------------------------------------------------------------------ diff = mean(0. No) - mean(1. Yes) t = 1.9584 Ho: diff = 0 degrees of freedom = 67 Ha: diff < 0 Ha: diff != 0 Ha: diff > 0 Pr(T < t) = 0.9728 Pr(|T| > |t|) = 0.0544 Pr(T > t) = 0.0272 . . * Ikke-parametrisk sammenligning . . ranksum bwt, by(smoke) Two-sample Wilcoxon rank-sum (Mann-Whitney) test smoke | obs rank sum expected -------------+--------------------------------- 0. No | 115 11915.5 10925 1. Yes | 74 6039.5 7030 -------------+--------------------------------- combined | 189 17955 17955 unadjusted variance 134741.67 adjustment for ties -11.98 ---------- adjusted variance 134729.69 Ho: bwt(smoke==0. No) = bwt(smoke==1. Yes) z = 2.699 Prob > |z| = 0.0070 . . * korrespondance mellem t-test og simpel regression . . ttest bwt, by(smoke) Two-sample t test with equal variances ------------------------------------------------------------------------------ Group | Obs Mean Std. Err. Std. Dev. [95% Conf. Interval] ---------+-------------------------------------------------------------------- 0. No | 115 3054.957 70.1625 752.409 2915.965 3193.948 1. Yes | 74 2772.297 76.70106 659.8075 2619.432 2925.162 ---------+-------------------------------------------------------------------- combined | 189 2944.286 53.02811 729.016 2839.679 3048.892 ---------+-------------------------------------------------------------------- diff | 282.6592 106.9544 71.66693 493.6515 ------------------------------------------------------------------------------ diff = mean(0. No) - mean(1. Yes) t = 2.6428 Ho: diff = 0 degrees of freedom = 187 Ha: diff < 0 Ha: diff != 0 Ha: diff > 0 Pr(T < t) = 0.9955 Pr(|T| > |t|) = 0.0089 Pr(T > t) = 0.0045 . xi: regress bwt i.smoke i.smoke _Ismoke_0-1 (naturally coded; _Ismoke_0 omitted) Source | SS df MS Number of obs = 189 -------------+------------------------------ F( 1, 187) = 6.98 Model | 3597444.33 1 3597444.33 Prob > F = 0.0089 Residual | 96317854.2 187 515068.739 R-squared = 0.0360 -------------+------------------------------ Adj R-squared = 0.0308 Total | 99915298.6 188 531464.354 Root MSE = 717.68 ------------------------------------------------------------------------------ bwt | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- _Ismoke_1 | -282.6592 106.9544 -2.64 0.009 -493.6515 -71.66693 _cons | 3054.957 66.92428 45.65 0.000 2922.933 3186.98 ------------------------------------------------------------------------------ . . * kan nu lave robust regressionsanalyse uden antagelse af normalitet . . xi: regress bwt i.smoke, robust i.smoke _Ismoke_0-1 (naturally coded; _Ismoke_0 omitted) Linear regression Number of obs = 189 F( 1, 187) = 7.40 Prob > F = 0.0071 R-squared = 0.0360 Root MSE = 717.68 ------------------------------------------------------------------------------ | Robust bwt | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- _Ismoke_1 | -282.6592 103.9124 -2.72 0.007 -487.6504 -77.66803 _cons | 3054.957 70.22935 43.50 0.000 2916.413 3193.5 ------------------------------------------------------------------------------ . . . . end of do-file