*! version 7.0.3 10June2001
* Written by Peter Cummings
/* dblpair.ado */
/* this version uses delta method variance estimator */
program define dblpair, rclass
	version 7.0
	syntax varlist(min=2 max=2 numeric) [if] [in], /*
	*/ [level(real .95)] driver(string) /*
	*/ group(varname) [oby(varlist)] [vby(varlist)]
	marksample touse
	tokenize `varlist'
	tempvar outcome
	qui gen byte `outcome' = `1' if `touse'
	tempvar expos
	qui gen byte `expos' = `2' if `touse'
	tempvar drivern
	qui gen byte `drivern'= `driver' if `touse'
	tempvar pass
	qui gen byte `pass' = `drivern'==0 if `touse'
	markout `touse' `pass' `oby' `vby'
	preserve
	qui keep if `touse'

	/* check that outcome is coded 0/1 */
	capture assert `outcome'==0 | `outcome'==1 | `outcome'==.
		if _rc~=0 {
			di in re "Outcome " in ye "`1'" /*
			*/ in re " not coded 0/1"
			exit 450
		}

	/* check exposure is coded 0/1 */
	capture assert `expos'==0 | `expos'==1 | `expos'==.
		if _rc~=0 {
			di in re "Exposure " in ye "`2'" /*
			*/ in re " not coded 0/1"
			exit 450
		}

	/* check that groups are never greater than 2 */
	sort `group'
	tempvar grpct
	qui by `group': gen `grpct' = _N
	capture assert `grpct' <3
		if _rc~=0 {
			di in re "Some groups are greater than 2"
			exit 459
		}


	/* convert 2 record format to 1 record format */
	sort `group' `pass'
	tempvar miss1 miss2
	qui by `group': gen byte `miss1' = /*
		*/ `touse'[2] == 0 | `expos'[2]==. | `outcome'[2]==.
	qui by `group': gen byte `miss2' = /*
		*/ `touse'[1] == 0 | `expos'[1]==. | `outcome'[1]==.
	qui replace `miss1' = . if `miss1' ==1
	qui replace `miss2' = . if `miss2' ==1
	markout `touse' `miss1' `miss2'
	tempvar dout dexp
	qui by `group': gen byte `dout' = `outcome'[1] if `touse'
	qui by `group': gen byte `dexp' = `expos'[1] if `touse'
	tempvar pout pexp
	qui by `group': gen byte `pout' = `outcome'[2] if `touse'
	qui by `group': gen byte `pexp' = `expos'[2] if `touse'

	/* deal with occupant by variables. Create a temporary
	variable for each confounder in occupant list and create driver
	and passenger versions */

	local oct: word count `oby'
	tokenize `oby'
	local i 1
	/* generate the new occupant variables and put their names into
	local macro stro */
	local stro = ""		/* collect all the new variable names */
	local strod= ""		/* collect the new driver variable names */
	local strop= ""		/* collect the new passenger var names */
	while `i' <= `oct' {
		tempvar dobyv`i' pobyv`i'
		qui by `group': gen int `dobyv`i'' = ``i''[1] if `touse'
		qui by `group': gen int `pobyv`i'' = ``i''[2] if `touse'
		local stro = "`stro' `dobyv`i'' `pobyv`i'' "
		local strod = "`strod' `dobyv`i''"
		local strop = "`strop' `pobyv`i''"
		local i = `i' + 1
		}

	/* change 'touse' to include only the driver record */
	tempvar dronly
	qui gen byte `dronly' = 1 if `pass' ==0
	/* use only records that have at least one dead occupant */
	tempvar onedead
	qui gen byte `onedead' = 1 if `pout'==1 | `dout'==1
	/* use only pairs that are discordant on the exposure */
	markout `touse' `dronly' `onedead'
	qui keep if `touse'
	tempvar prct
	qui count
	qui gen long `prct' = r(N)
	
	/* deal with vby, the vehicle variables */
	local vct: word count `vby'

	/* GENERATE CRUDE ESTIMATES */
	/* generate the driver belted to passenger unbelted ratio */
	tempvar a0 b0 c0 e0 f0 g0 ii0 j0 k0 m0 n0 o0
	tempvar aaa0 bbb0 ccc0 eee0 fff0 ggg0 iii0 jjj0 kkk0 mmm0 nnn0 ooo0
	tempvar dbru0    /* driver belted to passenger unbelted */
	tempvar duru0    /* driver unbelted to passenger unbelted */
	tempvar dru0     /* driver to passenger unbelted */
	tempvar vdru0   /* variance of ln dru */
	tempvar dbrb0    /* driver belted to passenger belted */
	tempvar durb0    /* driver unbelted to passenger belted */
	tempvar drb0     /* driver to passenger belted */
	tempvar vdrb0   /* variance of ln drb */

	/* a b c d */
	qui gen byte `aaa0' = `dexp'==1 & `dout'==1 & `pexp'==0 & `pout'==1
	qui gen long `a0' = sum(`aaa0')
	qui replace `a0'  = `a0'[_N]
	qui gen byte `bbb0' = `dexp'==1 & `dout'==0 & `pexp'==0 & `pout'==1
	qui gen long `b0' = sum(`bbb0')
	qui replace `b0'  = `b0'[_N]
	qui gen byte `ccc0' = `dexp'==1 & `dout'==1 & `pexp'==0 & `pout'==0
	qui gen long `c0' = sum(`ccc0')
	qui replace `c0'  = `c0'[_N]
	/* e f g h */
	qui gen byte `eee0' = `dexp'==0 & `dout'==1 & `pexp'==0 & `pout'==1
	qui gen long `e0' = sum(`eee0')
	qui replace `e0'  = `e0'[_N]
	qui gen byte `fff0' = `dexp'==0 & `dout'==0 & `pexp'==0 & `pout'==1
	qui gen long `f0' = sum(`fff0')
	qui replace `f0'  = `f0'[_N]
	qui gen byte `ggg0' = `dexp'==0 & `dout'==1 & `pexp'==0 & `pout'==0
	qui gen long `g0' = sum(`ggg0')
	qui replace `g0'  = `g0'[_N]
	/* i j k l */
	qui gen byte `iii0' = `dexp'==1 & `dout'==1 & `pexp'==1 & `pout'==1
	qui gen long `ii0' = sum(`iii0')
	qui replace `ii0'  = `ii0'[_N]
	qui gen byte `jjj0' = `dexp'==1 & `dout'==0 & `pexp'==1 & `pout'==1
	qui gen long `j0' = sum(`jjj0')
	qui replace `j0'  = `j0'[_N]
	qui gen byte `kkk0' = `dexp'==1 & `dout'==1 & `pexp'==1 & `pout'==0
	qui gen long `k0' = sum(`kkk0')
	qui replace `k0'  = `k0'[_N]
	/* m n o p */
	qui gen byte `mmm0' = `dexp'==0 & `dout'==1 & `pexp'==1 & `pout'==1
	qui gen long `m0' = sum(`mmm0')
	qui replace `m0'  = `m0'[_N]
	qui gen byte `nnn0' = `dexp'==0 & `dout'==0 & `pexp'==1 & `pout'==1
	qui gen long `n0' = sum(`nnn0')
	qui replace `n0'  = `n0'[_N]
	qui gen byte `ooo0' = `dexp'==0 & `dout'==1 & `pexp'==1 & `pout'==0
	qui gen long `o0' = sum(`ooo0')
	qui replace `o0'  = `o0'[_N]

	qui gen double `dbru0' = (`a0'+`c0')/(`a0'+`b0')
	qui gen double `duru0' = (`e0'+`g0')/(`e0'+`f0')
	qui gen double `dru0' = `dbru0'/`duru0'
	qui gen double `vdru0' = /*
		*/  [[[(`a0'*(`a0'+`b0'+`c0'))+(`b0'*`c0')]*(`f0'+`g0')] /*
		*/ + [[(`e0'*(`e0'+`f0'+`g0'))+(`f0'*`g0')]*(`b0'+`c0')]] /*
		*/ / [(`a0'+`c0')*(`a0'+`b0')*(`e0'+`f0')*(`e0'+`g0')]
	qui gen double `dbrb0' = (`ii0'+`k0')/(`ii0'+`j0')
	qui gen double `durb0' = (`m0'+`o0')/(`m0'+`n0')
	qui gen double `drb0' = `dbrb0'/`durb0'
	qui gen double `vdrb0' = /*
		*/  [[[(`ii0'*(`ii0'+`j0'+`k0'))+(`j0'*`k0')]*(`n0'+`o0')] /*
		*/ + [[(`m0'*(`m0'+`n0'+`o0'))+(`n0'*`o0')]*(`j0'+`k0')]] /*
		*/ / [(`ii0'+`k0')*(`ii0'+`j0')*(`m0'+`n0')*(`m0'+`o0')]

	/* temporary variables for passenger to driver estimates */
	tempvar pbru0    /* passenger belted to driver unbelted */
	tempvar puru0    /* passenger unbelted to driver unbelted */
	tempvar pru0     /* passenger to driver unbelted */
	tempvar vpru0   /* variance of ln pru */
	tempvar pbrb0    /* passenger belted to driver belted */
	tempvar purb0    /* passenger unbelted to driver belted */
	tempvar prb0     /* passenger to driver belted */
	tempvar vprb0   /* variance of ln prb */

	/* generate passenger to driver relative risk estimates */
	qui gen double `pbru0' = (`m0'+`n0')/(`m0'+`o0')
	qui gen double `puru0' = (`e0'+`f0')/(`e0'+`g0')
	qui gen double `pru0' = `pbru0'/`puru0'
	qui gen double `vpru0' = /*
		*/  [[[(`m0'*(`m0'+`o0'+`n0'))+(`o0'*`n0')]*(`f0'+`g0')] /*
		*/ + [[(`e0'*(`e0'+`f0'+`g0'))+(`f0'*`g0')]*(`o0'+`n0')]] /*
		*/ / [(`m0'+`n0')*(`m0'+`o0')*(`e0'+`f0')*(`e0'+`g0')]
	qui gen double `pbrb0' = (`ii0'+`j0')/(`ii0'+`k0')
	qui gen double `purb0' = (`a0'+`b0')/(`a0'+`c0')
	qui gen double `prb0' = `pbrb0'/`purb0'
	qui gen double `vprb0' = /*
		*/  [[[(`ii0'*(`ii0'+`j0'+`k0'))+(`j0'*`k0')]*(`c0'+`b0')] /*
		*/ + [[(`a0'*(`a0'+`c0'+`b0'))+(`c0'*`b0')]*(`j0'+`k0')]] /*
		*/ / [(`ii0'+`k0')*(`ii0'+`j0')*(`a0'+`c0')*(`a0'+`b0')]

	tempvar drr0		/* driver rr */
	tempvar vdrr0		/* variance of ln drr */
	tempvar drru0		/* upper CI for drr */
	tempvar drrl0		/* lower CI for drr */
	tempvar prr0		/* passenger rr */
	tempvar vprr0		/* variance of ln prr */
	tempvar prru0		/* upper CI for prr */
	tempvar prrl0		/* lower CI for prr */
	tempvar rr0		/* rr */
	
	qui gen double `drr0' = exp([ln(`dru0')*(1/`vdru0') /*
		*/ + ln(`drb0')*(1/`vdrb0')] /*
		*/ /[(1/`vdru0')+(1/`vdrb0')])
	qui replace `drr0' = `dru0' if `drb0'==.
	qui replace `drr0' = `drb0' if `dru0'==.
	qui gen double `vdrr0' = 1/[(1/`vdru0')+(1/`vdrb0')]
	qui replace `vdrr0' = `vdru0' if `vdrb0'==.
	qui replace `vdrr0' = `vdrb0' if `vdru0'==.
	qui gen double `drru0' = exp(ln(`drr0') /*
		*/ + invnorm(`level'*.5 + 0.5)*sqrt(`vdrr0'))
	qui gen double `drrl0' = exp(ln(`drr0') /*
		*/ - invnorm(`level'*.5 + 0.5)*sqrt(`vdrr0'))
	qui gen double `prr0' = exp([ln(`pru0')*(1/`vpru0') /*
		*/ + ln(`prb0')*(1/`vprb0')] /*
		*/ /[(1/`vpru0')+(1/`vprb0')])
	qui replace `prr0' = `pru0' if `prb0'==.
	qui replace `prr0' = `prb0' if `pru0'==.
	qui gen double `vprr0' = 1/[(1/`vpru0')+(1/`vprb0')]
	qui replace `vprr0' = `vpru0' if `vprb0'==.
	qui replace `vprr0' = `vprb0' if `vpru0'==.
		qui gen double `prru0' = exp(ln(`prr0') /*
		*/ + invnorm(`level'*.5 + 0.5)*sqrt(`vprr0'))
	qui gen double `prrl0' = exp(ln(`prr0') /*
		*/ - invnorm(`level'*.5 + 0.5)*sqrt(`vprr0'))
	qui gen double `rr0' = exp([ln(`drr0')*(1/`vdrr0') /*
		*/ + ln(`prr0')*(1/`vprr0')] /*
		*/ /[(1/`vdrr0')+(1/`vprr0')])

	return scalar drr = `drr0'
	return scalar vdrr = `vdrr0'
	return scalar drru = `drru0'
	return scalar drrl = `drrl0'
	return scalar prr = `prr0'
	return scalar vprr = `vprr0'
	return scalar prru = `prru0'
	return scalar prrl = `prrl0'
	return scalar rr = `rr0'
	return scalar prct = `prct'

	/* generate results by strata according
	to the oby and vby variables */
	/* start a big if/else loop here. Within the first part
		calculate and display the stratum specific estimates.
		The last part will just display crude estimates. */

	if "`stro'`vby'" ~="" {	/* large if/else starts here */
		tempvar strata
		qui egen int `strata' = group(`stro' `vby')
		qui summarize `strata'
		tempvar strmax
		qui gen `strmax' = r(max)

	/* generate counts by stratum */
	/* generate the driver belted to passenger unbelted ratio */
	tempvar last
	tempvar a b c e f g ii j k m n o
	tempvar aaa bbb ccc eee fff ggg iii jjj kkk mmm nnn ooo
	tempvar dbru    /* driver belted to passenger unbelted */
	tempvar duru    /* driver unbelted to passenger unbelted */
	tempvar dru     /* driver to passenger unbelted */
	tempvar vdru    /* variance of ln dru */
	tempvar dbrb    /* driver belted to passenger belted */
	tempvar durb    /* driver unbelted to passenger belted */
	tempvar drb     /* driver to passenger belted */
	tempvar vdrb    /* variance of ln drb */

	/* a b c d */
	sort `strata'
	tempvar last
	qui gen byte `last'=0
	qui by `strata': replace `last'=1 if _n== _N
	qui by `strata': gen byte `aaa' = /*
		*/ `dexp'==1 & `dout'==1 & `pexp'==0 & `pout'==1
	qui by `strata': gen long `a' = sum(`aaa')
	qui by `strata': replace `a'  = `a'[_N]
	qui by `strata': gen byte `bbb' = /*
		*/ `dexp'==1 & `dout'==0 & `pexp'==0 & `pout'==1
	qui by `strata': gen long `b' = sum(`bbb')
	qui by `strata': replace `b'  = `b'[_N]
	qui by `strata': gen byte `ccc' = /*
		*/ `dexp'==1 & `dout'==1 & `pexp'==0 & `pout'==0
	qui by `strata': gen long `c' = sum(`ccc')
	qui by `strata': replace `c'  = `c'[_N]
	/* e f g h */
	qui by `strata': gen byte `eee' = /*
		*/ `dexp'==0 & `dout'==1 & `pexp'==0 & `pout'==1
	qui by `strata': gen long `e' = sum(`eee')
	qui by `strata': replace `e'  = `e'[_N]
	qui by `strata': gen byte `fff' = /*
		*/ `dexp'==0 & `dout'==0 & `pexp'==0 & `pout'==1
	qui by `strata': gen long `f' = sum(`fff')
	qui by `strata': replace `f'  = `f'[_N]
	qui by `strata': gen byte `ggg' = /*
		*/ `dexp'==0 & `dout'==1 & `pexp'==0 & `pout'==0
	qui by `strata': gen long `g' = sum(`ggg')
	qui by `strata': replace `g'  = `g'[_N]
	/* i j k l */
	qui by `strata': gen byte `iii' = /*
		*/ `dexp'==1 & `dout'==1 & `pexp'==1 & `pout'==1
	qui by `strata': gen long `ii' = sum(`iii')
	qui by `strata': replace `ii'  = `ii'[_N]
	qui by `strata': gen byte `jjj' = /*
		*/ `dexp'==1 & `dout'==0 & `pexp'==1 & `pout'==1
	qui by `strata': gen long `j' = sum(`jjj')
	qui by `strata': replace `j'  = `j'[_N]
	qui by `strata': gen byte `kkk' = /*
		*/ `dexp'==1 & `dout'==1 & `pexp'==1 & `pout'==0
	qui by `strata': gen long `k' = sum(`kkk')
	qui by `strata': replace `k'  = `k'[_N]
	/* m n o p */
	qui by `strata': gen byte `mmm' = /*
		*/ `dexp'==0 & `dout'==1 & `pexp'==1 & `pout'==1
	qui by `strata': gen long `m' = sum(`mmm')
	qui by `strata': replace `m'  = `m'[_N]
	qui by `strata': gen byte `nnn' = /*
		*/ `dexp'==0 & `dout'==0 & `pexp'==1 & `pout'==1
	qui by `strata': gen long `n' = sum(`nnn')
	qui by `strata': replace `n'  = `n'[_N]
	qui by `strata': gen byte `ooo' = /*
		*/ `dexp'==0 & `dout'==1 & `pexp'==1 & `pout'==0
	qui by `strata': gen long `o' = sum(`ooo')
	qui by `strata': replace `o'  = `o'[_N]

	local i 1
	while `i'<=`strmax' {
		qui count if `strata' ==`i'
		tempvar prct`i'
		qui gen long prct`i' = r(N)
		return scalar prct`i' = r(N)
		local i = `i' +1
		}

	qui keep if `last'==1

	qui gen double `dbru' = (`a'+`c')/(`a'+`b')
	qui gen double `duru' = (`e'+`g')/(`e'+`f')
	qui gen double `dru' = `dbru'/`duru'
	qui gen double `vdru' = /*
		*/  [[[(`a'*(`a'+`b'+`c'))+(`b'*`c')]*(`f'+`g')] /*
		*/ + [[(`e'*(`e'+`f'+`g'))+(`f'*`g')]*(`b'+`c')]] /*
		*/ / [(`a'+`c')*(`a'+`b')*(`e'+`f')*(`e'+`g')]
	qui gen double `dbrb' = (`ii'+`k')/(`ii'+`j')
	qui gen double `durb' = (`m'+`o')/(`m'+`n')
	qui gen double `drb' = `dbrb'/`durb'
	qui gen double `vdrb' = /*
		*/  [[[(`ii'*(`ii'+`j'+`k'))+(`j'*`k')]*(`n'+`o')] /*
		*/ + [[(`m'*(`m'+`n'+`o'))+(`n'*`o')]*(`j'+`k')]] /*
		*/ / [(`ii'+`k')*(`ii'+`j')*(`m'+`n')*(`m'+`o')]

	/* temporary variables for passenger to driver estimates */
	tempvar pbru    /* passenger belted to driver unbelted */
	tempvar puru    /* passenger unbelted to driver unbelted */
	tempvar pru     /* passenger to driver unbelted */
	tempvar vpru    /* variance of ln pru */
	tempvar pbrb    /* passenger belted to driver belted */
	tempvar purb    /* passenger unbelted to driver belted */
	tempvar prb     /* passenger to driver belted */
	tempvar vprb    /* variance of ln prb */

	/* generate passenger to driver relative risk estimates */
	qui gen double `pbru' = (`m'+`n')/(`m'+`o')
	qui gen double `puru' = (`e'+`f')/(`e'+`g')
	qui gen double `pru' = `pbru'/`puru'
	qui gen double `vpru' = /*
		*/  [[[(`m'*(`m'+`o'+`n'))+(`o'*`n')]*(`f'+`g')] /*
		*/ + [[(`e'*(`e'+`f'+`g'))+(`f'*`g')]*(`o'+`n')]] /*
		*/ / [(`m'+`n')*(`m'+`o')*(`e'+`f')*(`e'+`g')]
	qui gen double `pbrb' = (`ii'+`j')/(`ii'+`k')
	qui gen double `purb' = (`a'+`b')/(`a'+`c')
	qui gen double `prb' = `pbrb'/`purb'
	qui gen double `vprb' = /*
		*/  [[[(`ii'*(`ii'+`j'+`k'))+(`j'*`k')]*(`c'+`b')] /*
		*/ + [[(`a'*(`a'+`c'+`b'))+(`c'*`b')]*(`j'+`k')]] /*
		*/ / [(`ii'+`k')*(`ii'+`j')*(`a'+`c')*(`a'+`b')]

	tempvar drr		/* driver rr */
	tempvar vdrr		/* variance of ln drr */
	tempvar drru		/* upper CI for drr */
	tempvar drrl		/* lower CI for drr */
	tempvar prr		/* passenger rr */
	tempvar vprr		/* variance of ln prr */
	tempvar prru		/* upper CI for prr */
	tempvar prrl		/* lower CI for prr */
	tempvar rr		/* rr */
	
	qui gen double `drr' = exp([ln(`dru')*(1/`vdru') /*
		*/ + ln(`drb')*(1/`vdrb')] /*
		*/ /[(1/`vdru')+(1/`vdrb')])
	qui replace `drr' = `dru' if `drb'==.
	qui replace `drr' = `drb' if `dru'==.
	qui gen double `vdrr' = 1/[(1/`vdru')+(1/`vdrb')]
	qui replace `vdrr' = `vdru' if `vdrb'==.
	qui replace `vdrr' = `vdrb' if `vdru'==.
	qui gen double `drru' = exp(ln(`drr') /*
		*/ + invnorm(`level'*.5 + 0.5)*sqrt(`vdrr'))
	qui gen double `drrl' = exp(ln(`drr') /*
		*/ - invnorm(`level'*.5 + 0.5)*sqrt(`vdrr'))
	qui gen double `prr' = exp([ln(`pru')*(1/`vpru') /*
		*/ + ln(`prb')*(1/`vprb')] /*
		*/ /[(1/`vpru')+(1/`vprb')])
	qui replace `prr' = `pru' if `prb'==.
	qui replace `prr' = `prb' if `pru'==.
	qui gen double `vprr' = 1/[(1/`vpru')+(1/`vprb')]
	qui replace `vprr' = `vpru' if `vprb'==.
	qui replace `vprr' = `vprb' if `vpru'==.
	qui gen double `prru' = exp(ln(`prr') /*
		*/ + invnorm(`level'*.5 + 0.5)*sqrt(`vprr'))
	qui gen double `prrl' = exp(ln(`prr') /*
		*/ - invnorm(`level'*.5 + 0.5)*sqrt(`vprr'))
	qui gen double `rr' = exp([ln(`drr')*(1/`vdrr') /*
		*/ + ln(`prr')*(1/`vprr')] /*
		*/ /[(1/`vdrr')+(1/`vprr')])
		
	/* now combine results across strata using variance 
	weighted summaries. Use "a" for "adjusted". */
	
	tempvar ladrrt		/* top part of ln drr calculation */
	qui gen double `ladrrt' = sum((1/`vdrr') * ln(`drr'))
	qui replace `ladrrt' = `ladrrt'[_N]
	tempvar ladrrb	 	/* bottom part of ln drr calc */
	qui gen double `ladrrb' = sum(1/`vdrr')
	qui replace `ladrrb' = `ladrrb'[_N]
	tempvar adrr
	qui gen double `adrr' = exp(`ladrrt'/`ladrrb')
	/* now combine variance of this estimate, which
	is just the inverse of the sum of the weights */
	tempvar vadrr		/* variance of ln adrr */
	qui gen double `vadrr' = (1/`ladrrb')
	tempvar adrru
	qui gen double `adrru' = exp(ln(`adrr') /*
		*/ + invnorm(`level'*.5 + 0.5)*sqrt(`vadrr'))
	tempvar adrrl
	qui gen double `adrrl' = exp(ln(`adrr') /*	
		*/ - invnorm(`level'*.5 + 0.5)*sqrt(`vadrr'))
	
	tempvar laprrt	/* top part of ln aprr calculation */
	qui gen double `laprrt' = sum((1/`vprr') * ln(`prr'))
	qui replace `laprrt' = `laprrt'[_N]
	tempvar laprrb 	/* bottom part of ln aprr calc */
	qui gen double `laprrb' = sum(1/`vprr')
	qui replace `laprrb' = `laprrb'[_N]
	tempvar aprr
	qui gen double `aprr' = exp(`laprrt'/`laprrb')
	/* now combine variance of this estimate, which
	is just the inverse of the sum of the weights */
	tempvar vaprr		/* variance of ln aprr */
	qui gen double `vaprr' = (1/`laprrb')
	tempvar aprru
	qui gen double `aprru' = exp(ln(`aprr') /*
		*/ + invnorm(`level'*.5 + 0.5)*sqrt(`vaprr'))
	tempvar aprrl
	qui gen double `aprrl' = exp(ln(`aprr') /*
		*/ - invnorm(`level'*.5 + 0.5)*sqrt(`vaprr'))

	tempvar arr
	qui gen double `arr' = exp([ln(`adrr')*(1/`vadrr') /*
		*/ + ln(`aprr')*(1/`vaprr')]/[(1/`vadrr')+(1/`vaprr')])

	/* tests of homogeneity */
	tempvar dchi pchi ddf pdf dpchi ppchi
	qui gen double `dchi' = sum(((ln(`drr')-ln(`adrr'))^2)/`vdrr')
	qui replace `dchi' = `dchi'[_N]
	qui gen double `pchi' = sum(((ln(`prr')-ln(`aprr'))^2)/`vprr')
	qui replace `pchi' = `pchi'[_N]
	qui count if `drr'~=.
	qui gen int `ddf' = r(N) -1
	qui count if `prr'~=.
	qui gen int `pdf' = r(N) -1
	qui gen double `dpchi' = chi2tail(`ddf',`dchi')
	qui gen double `ppchi' = chi2tail(`pdf',`pchi')

	sort `strata'
	local i 1
	while `i'<=`strmax' {
		return scalar drr`i' = `drr'[`i']
		return scalar vdrr`i' = `vdrr'[`i']
		return scalar drru`i' = `drru'[`i']
		return scalar drrl`i' = `drrl'[`i']
		return scalar prr`i' = `prr'[`i']
		return scalar vprr`i' = `vprr'[`i']
		return scalar prru`i' = `prru'[`i']
		return scalar prrl`i' = `prrl'[`i']
		return scalar rr`i' = `rr'[`i']
		local i = `i' +1
		}

	return scalar adrr = `adrr'[_N]
	return scalar avdrr = `vadrr'[_N]
	return scalar adrru = `adrru'[_N]
	return scalar adrrl = `adrrl'[_N]
	return scalar aprr = `aprr'[_N]
	return scalar avprr = `vaprr'[_N]
	return scalar aprru = `aprru'[_N]
	return scalar aprrl = `aprrl'[_N]
	return scalar arr = `arr'[_N]
	
	/* at this point, compute a new crude rr which uses
	data only from strata which have either a prr variance
	or a drr variance */
	tempvar a0n b0n c0n e0n f0n g0n ii0n j0n k0n m0n n0n o0n
	tempvar dbru0n duru0n dru0n dbrb0n durb0n drb0n
	tempvar vdru0n vdrb0n
	gsort -`vdrr', mfirst
	qui gen long `a0n' = sum(`a') if `vdrr'~=.
	qui replace `a0n'  = `a0n'[_N]
	qui gen long `b0n' = sum(`b') if `vdrr'~=.
	qui replace `b0n'  = `b0n'[_N]
	qui gen long `c0n' = sum(`c') if `vdrr'~=.
	qui replace `c0n'  = `c0n'[_N]
	qui gen long `e0n' = sum(`e') if `vdrr'~=.
	qui replace `e0n'  = `e0n'[_N]
	qui gen long `f0n' = sum(`f') if `vdrr'~=.
	qui replace `f0n'  = `f0n'[_N]
	qui gen long `g0n' = sum(`g') if `vdrr'~=.
	qui replace `g0n'  = `g0n'[_N]
	qui gen long `ii0n' = sum(`ii') if `vdrr'~=.
	qui replace `ii0n'  = `ii0n'[_N]
	qui gen long `j0n' = sum(`j') if `vdrr'~=.
	qui replace `j0n'  = `j0n'[_N]
	qui gen long `k0n' = sum(`k') if `vdrr'~=.
	qui replace `k0n'  = `k0n'[_N]
	qui gen long `m0n' = sum(`m') if `vdrr'~=.
	qui replace `m0n'  = `m0n'[_N]
	qui gen long `n0n' = sum(`n') if `vdrr'~=.
	qui replace `n0n'  = `n0n'[_N]
	qui gen long `o0n' = sum(`o') if `vdrr'~=.
	qui replace `o0n'  = `o0n'[_N]

	qui gen double `dbru0n' = (`a0n'+`c0n')/(`a0n'+`b0n')
	qui gen double `duru0n' = (`e0n'+`g0n')/(`e0n'+`f0n')
	qui gen double `dru0n' = `dbru0n'/`duru0n'
	qui gen double `vdru0n' = /*
		*/  [[[(`a0n'*(`a0n'+`b0n'+`c0n'))+(`b0n'*`c0n')]*(`f0n'+`g0n')] /*
		*/ + [[(`e0n'*(`e0n'+`f0n'+`g0n'))+(`f0n'*`g0n')]*(`b0n'+`c0n')]] /*
		*/ / [(`a0n'+`c0n')*(`a0n'+`b0n')*(`e0n'+`f0n')*(`e0n'+`g0n')]
	qui gen double `dbrb0n' = (`ii0n'+`k0n')/(`ii0n'+`j0n')
	qui gen double `durb0n' = (`m0n'+`o0n')/(`m0n'+`n0n')
	qui gen double `drb0n' = `dbrb0n'/`durb0n'
	qui gen double `vdrb0n' = /*
		*/  [[[(`ii0n'*(`ii0n'+`j0n'+`k0n'))+(`j0n'*`k0n')]*(`n0n'+`o0n')] /*
		*/ + [[(`m0n'*(`m0n'+`n0n'+`o0n'))+(`n0n'*`o0n')]*(`j0n'+`k0n')]] /*
		*/ / [(`ii0n'+`k0n')*(`ii0n'+`j0n')*(`m0n'+`n0n')*(`m0n'+`o0n')]

	/* temporary variables for passenger to driver estimates.
	These variables are for a new crude estimate that uses
	stratified data only. */
	tempvar pbru0n    /* passenger belted to driver unbelted */
	tempvar puru0n    /* passenger unbelted to driver unbelted */
	tempvar pru0n     /* passenger to driver unbelted */
	tempvar vpru0n    /* variance of ln pru */
	tempvar pbrb0n    /* passenger belted to driver belted */
	tempvar purb0n    /* passenger unbelted to driver belted */
	tempvar prb0n     /* passenger to driver belted */
	tempvar vprb0n    /* variance of ln prb */

	/* I will redo a0n through o0n now for passengers */
	gsort -`vprr', mfirst
	qui replace `a0n' = sum(`a') if `vprr'~=.
	qui replace `a0n'  = `a0n'[_N]
	qui replace `b0n' = sum(`b') if `vprr'~=.
	qui replace `b0n'  = `b0n'[_N]
	qui replace `c0n' = sum(`c') if `vprr'~=.
	qui replace `c0n'  = `c0n'[_N]
	qui replace `e0n' = sum(`e') if `vprr'~=.
	qui replace `e0n'  = `e0n'[_N]
	qui replace `f0n' = sum(`f') if `vprr'~=.
	qui replace `f0n'  = `f0n'[_N]
	qui replace `g0n' = sum(`g') if `vprr'~=.
	qui replace `g0n'  = `g0n'[_N]
	qui replace `ii0n' = sum(`ii') if `vprr'~=.
	qui replace `ii0n'  = `ii0n'[_N]
	qui replace `j0n' = sum(`j') if `vprr'~=.
	qui replace `j0n'  = `j0n'[_N]
	qui replace `k0n' = sum(`k') if `vprr'~=.
	qui replace `k0n'  = `k0n'[_N]
	qui replace `m0n' = sum(`m') if `vprr'~=.
	qui replace `m0n'  = `m0n'[_N]
	qui replace `n0n' = sum(`n') if `vprr'~=.
	qui replace `n0n'  = `n0n'[_N]
	qui replace `o0n' = sum(`o') if `vprr'~=.
	qui replace `o0n'  = `o0n'[_N]

	/* generate passenger to driver relative risk estimates.
	These are for a crude estimate that uses the stratified data. */
	qui gen double `pbru0n' = (`m0n'+`n0n')/(`m0n'+`o0n')
	qui gen double `puru0n' = (`e0n'+`f0n')/(`e0n'+`g0n')
	qui gen double `pru0n' = `pbru0n'/`puru0n'
	qui gen double `vpru0n' = /*
		*/  [[[(`m0n'*(`m0n'+`o0n'+`n0n'))+(`o0n'*`n0n')]*(`f0n'+`g0n')] /*
		*/ + [[(`e0n'*(`e0n'+`f0n'+`g0n'))+(`f0n'*`g0n')]*(`o0n'+`n0n')]] /*
		*/ / [(`m0n'+`n0n')*(`m0n'+`o0n')*(`e0n'+`f0n')*(`e0n'+`g0n')]
	qui gen double `pbrb0n' = (`ii0n'+`j0n')/(`ii0n'+`k0n')
	qui gen double `purb0n' = (`a0n'+`b0n')/(`a0n'+`c0n')
	qui gen double `prb0n' = `pbrb0n'/`purb0n'
	qui gen double `vprb0n' = /*
		*/  [[[(`ii0n'*(`ii0n'+`j0n'+`k0n'))+(`j0n'*`k0n')]*(`c0n'+`b0n')] /*
		*/ + [[(`a0n'*(`a0n'+`c0n'+`b0n'))+(`c0n'*`b0n')]*(`j0n'+`k0n')]] /*
		*/ / [(`ii0n'+`k0n')*(`ii0n'+`j0n')*(`a0n'+`c0n')*(`a0n'+`b0n')]

	tempvar drr0n		/* driver rr */
	tempvar vdrr0n		/* variance of ln drr */
	tempvar drru0n		/* upper CI for drr */
	tempvar drrl0n		/* lower CI for drr */
	tempvar prr0n		/* passenger rr */
	tempvar vprr0n		/* variance of ln prr */
	tempvar prru0n		/* upper CI for prr */
	tempvar prrl0n		/* lower CI for prr */
	tempvar rr0n		/* rr */
	
	qui gen double `drr0n' = exp([ln(`dru0n')*(1/`vdru0n') /*
		*/ + ln(`drb0n')*(1/`vdrb0n')] /*
		*/ /[(1/`vdru0n')+(1/`vdrb0n')])
	qui replace `drr0n' = `dru0n' if `drb0n'==.
	qui replace `drr0n' = `drb0n' if `dru0n'==.
	qui gen double `vdrr0n' = 1/[(1/`vdru0n')+(1/`vdrb0n')]
	qui replace `vdrr0n' = `vdru0n' if `vdrb0n'==.
	qui replace `vdrr0n' = `vdrb0n' if `vdru0n'==.
	qui gen double `drru0n' = exp(ln(`drr0n') /*
		*/ + invnorm(`level'*.5 + 0.5)*sqrt(`vdrr0n'))
	qui gen double `drrl0n' = exp(ln(`drr0n') /*
		*/ - invnorm(`level'*.5 + 0.5)*sqrt(`vdrr0n'))
	qui gen double `prr0n' = exp([ln(`pru0n')*(1/`vpru0n') /*
		*/ + ln(`prb0n')*(1/`vprb0n')] /*
		*/ /[(1/`vpru0n')+(1/`vprb0n')])
	qui replace `prr0n' = `pru0n' if `prb0n'==.
	qui replace `prr0n' = `prb0n' if `pru0n'==.
	qui gen double `vprr0n' = 1/[(1/`vpru0n')+(1/`vprb0n')]
	qui replace `vprr0n' = `vpru0n' if `vprb0n'==.
	qui replace `vprr0n' = `vprb0n' if `vpru0n'==.
		qui gen double `prru0n' = exp(ln(`prr0n') /*
		*/ + invnorm(`level'*.5 + 0.5)*sqrt(`vprr0n'))
	qui gen double `prrl0n' = exp(ln(`prr0n') /*
		*/ - invnorm(`level'*.5 + 0.5)*sqrt(`vprr0n'))
	qui gen double `rr0n' = exp([ln(`drr0n')*(1/`vdrr0n') /*
		*/ + ln(`prr0n')*(1/`vprr0n')] /*
		*/ /[(1/`vdrr0n')+(1/`vprr0n')])

	return scalar drr0n = `drr0n'
	return scalar vdrr0n = `vdrr0n'
	return scalar drru0n = `drru0n'
	return scalar drrl0n = `drrl0n'
	return scalar prr0n = `prr0n'
	return scalar vprr0n = `vprr0n'
	return scalar prru0n = `prru0n'
	return scalar prrl0n = `prrl0n'
	return scalar rr0n = `rr0n'

	/* this ends the section of new crude estimates */

	/* create macros for value labels for strata display */

	local names `oby' `oby' `vby'
	tokenize `names'
 	capture local lbl1 : value label `1'
	capture local lbl2 : value label `2'
	capture local lbl3 : value label `3'
	capture local lbl4 : value label `4'
	capture local lbl5 : value label `5'
	capture local lbl6 : value label `6'
		
	/* confine output length to 72 characters */
	di
	local c1 = 73 - (8 + length("Pairs used = "))
	di as text "Double-pair method" _col(`c1') /*
		*/ "Pairs used = " as result %8.0g `prct'
	di as text "Stratified by: `oby' `vby'
	di as text "{hline 8}{c TT}{hline 63}"

	if `oct' ~= 0 & `vct' ~= 0 {
		local colp = 11 + 9*`oct'	/* passenger column */
		local colv = 11 + 2*9*`oct'	/* vehicle column */
		di as text _col(9)"{c |}" _col(11)"Driver" /*
			*/ _col(`colp')"Pass"  _col(`colv')"Vehicle"
	}
	else if `oct'==0 & `vct' ~= 0 {
		di as text _col(9)"{c |}" _col(11)"Vehicle"
	}
	else {
		local colp = 11 + 9*`oct'	/* passenger column */
		di as text _col(9)"{c |}" _col(11)"Driver" /*
			*/ _col(`colp')"Pass"
	}

	/* variable list will be 2*oct + 1*vct */
	tokenize `oby' `oby' `vby'
	di as text "stratum {c |}" _col(11)"`1'" _col(20)"`2'" /*
		*/ _col(29)"`3'" _col(38)"`4'" /*
		*/ _col(47)"`5'" _col(56)"`6'" _col(65)"count"
	di as text "{hline 8}{c +}{hline 63}"

	local totct: word count `oby' `oby' `vby'
	tokenize `strod' `strop' `vby'
	sort `strata'
	if `totct' == 6 {
		label values `1' `lbl1'		/* label values */
		label values `2' `lbl2'
		label values `3' `lbl3'
		label values `4' `lbl4'
		label values `5' `lbl5'
		label values `6' `lbl6'
		local i 1
		while `i' <=`strmax' {
		if "`lbl1'" ~= "" {
			local disp1 = `1'[`i']
			local dsplbl1 : label `labl1' `disp1'
			}
		else {
			capture local dsplbl1 = `1'[`i']
		}
		if "`lbl2'" ~= "" {
			local disp2 = `2'[`i']
			local dsplbl2 : label `labl2' `disp2'
			}
		else {
			capture local dsplbl2 = `2'[`i']
		}
		if "`lbl3'" ~= "" {
			local disp3 = `3'[`i']
			local dsplbl3 : label `labl3' `disp3'
			}
		else {
			capture local dsplbl3 = `3'[`i']
		}
		if "`lbl4'" ~= "" {
			local disp4 = `4'[`i']
			local dsplbl4 : label `labl4' `disp4'
			}
		else {
			capture local dsplbl4 = `4'[`i']
		}
		if "`lbl5'" ~= "" {
			local disp5 = `5'[`i']
			local dsplbl5 : label `labl5' `disp5'
			}
		else {
			capture local dsplbl5 = `5'[`i']
		}
		if "`lbl6'" ~= "" {
			local disp6 = `6'[`i']
			local dsplbl6 : label `labl6' `disp6'
			}
		else {
			capture local dsplbl6 = `6'[`i']
		}
		
		di as result `stratum'[`i'] as text _col(9)"{c |}" 
			*/ as result /*
			*/ _col(11)"`dsplbl1'" /*
			*/ _col(20)"`dsplbl2'" /*
			*/ _col(29)"`dsplbl3'" /*
			*/ _col(38)"`dsplbl4'" /*
			*/ _col(47)"`dsplbl5'" /*
			*/ _col(56)"`dsplbl6'" /*
			*/ _col(65) prct`i'[`i']
		local i = `i'+1
		}
	}
	else if `totct' == 5 {
		label values `1' `lbl1'		/* label values */
		label values `2' `lbl2'
		label values `3' `lbl3'
		label values `4' `lbl4'
		label values `5' `lbl5'
		local i 1
		while `i' <=`strmax' {
		if "`lbl1'" ~= "" {
			local disp1 = `1'[`i']
			local dsplbl1 : label `lbl1' `disp1'
			}
		else {
			capture local dsplbl1 = `1'[`i']
		}
		if "`lbl2'" ~= "" {
			local disp2 = `2'[`i']
			local dsplbl2 : label `lbl2' `disp2'
			}
		else {
			capture local dsplbl2 = `2'[`i']
		}
		if "`lbl3'" ~= "" {
			local disp3 = `3'[`i']
			local dsplbl3 : label `lbl3' `disp3'
			}
		else {
			capture local dsplbl3 = `3'[`i']
		}
		if "`lbl4'" ~= "" {
			local disp4 = `4'[`i']
			local dsplbl4 : label `lbl4' `disp4'
			}
		else {
			capture local dsplbl4 = `4'[`i']
		}
		if "`lbl5'" ~= "" {
			local disp5 = `5'[`i']
			local dsplbl5 : label `lbl5' `disp5'
			}
		else {
			capture local dsplbl5 = `5'[`i']
		}
		
		di as result `stratum'[`i'] as text _col(9)"{c |}" /*
			*/ as result /*
			*/ _col(11)"`dsplbl1'" /*
			*/ _col(20)"`dsplbl2'" /*
			*/ _col(29)"`dsplbl3'" /*
			*/ _col(38)"`dsplbl4'" /*
			*/ _col(47)"`dsplbl5'" /*
			*/ _col(65) prct`i'[`i']
		local i = `i'+1
		}
	}
	else if `totct' == 4 {
		label values `1' `lbl1'		/* label values */
		label values `2' `lbl2'
		label values `3' `lbl3'
		label values `4' `lbl4'
		local i 1
		while `i' <=`strmax' {
		if "`lbl1'" ~= "" {
			local disp1 = `1'[`i']
			local dsplbl1 : label `lbl1' `disp1'
			}
		else {
			capture local dsplbl1 = `1'[`i']
		}
		if "`lbl2'" ~= "" {
			local disp2 = `2'[`i']
			local dsplbl2 : label `lbl2' `disp2'
			}
		else {
			capture local dsplbl2 = `2'[`i']
		}
		if "`lbl3'" ~= "" {
			local disp3 = `3'[`i']
			local dsplbl3 : label `lbl3' `disp3'
			}
		else {
			capture local dsplbl3 = `3'[`i']
		}
		if "`lbl4'" ~= "" {
			local disp4 = `4'[`i']
			local dsplbl4 : label `lbl4' `disp4'
			}
		else {
			capture local dsplbl4 = `4'[`i']
		}
		
		di as result `stratum'[`i'] as text _col(9)"{c |}" /*
			*/ as result /*
			*/ _col(11)"`dsplbl1'" /*
			*/ _col(20)"`dsplbl2'" /*
			*/ _col(29)"`dsplbl3'" /*
			*/ _col(38)"`dsplbl4'" /*
			*/ _col(65) prct`i'[`i']
		local i = `i'+1
		}
	}
	else if `totct' == 3 {
		label values `1' `lbl1'		/* label values */
		label values `2' `lbl2'
		label values `3' `lbl3'
		local i 1
		while `i' <=`strmax' {
		if "`lbl1'" ~= "" {
			local disp1 = `1'[`i']
			local dsplbl1 : label `lbl1' `disp1'
			}
		else {
			capture local dsplbl1 = `1'[`i']
		}
		if "`lbl2'" ~= "" {
			local disp2 = `2'[`i']
			local dsplbl2 : label `lbl2' `disp2'
			}
		else {
			capture local dsplbl2 = `2'[`i']
		}
		if "`lbl3'" ~= "" {
			local disp3 = `3'[`i']
			local dsplbl3 : label `lbl3' `disp3'
			}
		else {
			capture local dsplbl3 = `3'[`i']
		}
		
		di as result `stratum'[`i'] as text _col(9)"{c |}" as result /*
			*/ _col(11)"`dsplbl1'" /*
			*/ _col(20)"`dsplbl2'" /*
			*/ _col(29)"`dsplbl3'" /*
			*/ _col(65) prct`i'[`i']
		local i = `i'+1
		}
	}
	else if `totct' == 2 {
		label values `1' `lbl1'		/* label values */
		label values `2' `lbl2'
		local i 1
		while `i' <=`strmax' {
		if "`lbl1'" ~= "" {
			local disp1 = `1'[`i']
			local dsplbl1 : label `lbl1' `disp1'
			}
		else {
			capture local dsplbl1 = `1'[`i']
		}
		if "`lbl2'" ~= "" {
			local disp2 = `2'[`i']
			local dsplbl2 : label `lbl2' `disp2'
			}
		else {
			capture local dsplbl2 = `2'[`i']
		}
		
		di as result `stratum'[`i'] as text _col(9)"{c |}" as result /*
			*/ _col(11)"`dsplbl1'" /*
			*/ _col(20)"`dsplbl2'" /*
			*/ _col(65) prct`i'[`i']
		local i = `i'+1
		}
	}
	else {
		label values `1' `lbl1'		/* label values */
		local i 1
		while `i' <=`strmax' {
		if "`lbl1'" ~= "" {
			local disp1 = `1'[`i']
			local dsplbl1 : label `lbl1' `disp1'
			}
		else {
			capture local dsplbl1 = `1'[`i']
		}		

		di as result `stratum'[`i'] as text _col(9)"{c |}" as result /*
			*/ _col(11)"`dsplbl1'" /*
			*/ _col(65) prct`i'[`i']
		local i = `i'+1
		}
	}

	di as text "{hline 8}{c BT}{hline 63}"
	di
	local levpc = `level'*100
	di as text "Relative Risk estimates" /*
		*/ _col(39)"Confidence interval level = " /*
		*/ %4.1f as result `levpc' " %"
	di as text "{hline 8}{c TT}{hline 63}"
	di as text "stratum {c |}" _col(11)"dRR" _col(19)"[Conf. Interval]" /*
		*/ _col(37)"pRR" _col(45)"[Conf. Interval]" /*
		*/ _col(64)"RR"
	di as text "{hline 8}{c +}{hline 63}"
	local i 1
	while `i' <=`strmax' {
		di as result `stratum'[`i'] as text _col(9)"{c |}" as result /*
			*/ _col(11) %5.4f `drr'[`i'] /*
			*/ _col(19) "[" as result %5.4f `drrl'[`i'] /*
			*/ "," /*
			*/ as result _col(28) %5.4f `drru'[`i'] "]" /*
			*/ as result _col(37) %5.4f `prr'[`i'] /*
			*/ _col(45) "[" as result %5.4f `prrl'[`i'] /*
			*/ "," /*
			*/ as result _col(54) %5.4f `prru'[`i'] "]" /*
			*/ as result _col(64) %5.4f `rr'[`i']
		local i = `i'+1
		}
	di as text "{hline 8}{c +}{hline 63}"
	di as text "crude" _col(9) "{c |}" as result /*
			*/ _col(11) %5.4f `drr0' /*
			*/ _col(19) "[" %5.4f `drrl0' "," /*
			*/ _col(28) %5.4f `drru0' "]" /*
			*/ _col(37) %5.4f `prr0' /*
			*/ _col(45) "[" %5.4f `prrl0' "," /*
			*/ _col(54) %5.4f `prru0' "]" /*
			*/ _col(64) %5.4f `rr0'
	di as text "crudenew{c |}" as result /*
			*/ _col(11) %5.4f `drr0n' /*
			*/ _col(19) "[" %5.4f `drrl0n' "," /*
			*/ _col(28) %5.4f `drru0n' "]" /*
			*/ _col(37) %5.4f `prr0n' /*
			*/ _col(45) "[" %5.4f `prrl0n' "," /*
			*/ _col(54) %5.4f `prru0n' "]" /*
			*/ _col(64) %5.4f `rr0n'
	di as text "adjusted{c |}" as result /*
			*/ _col(11) %5.4f `adrr' /*
			*/ _col(19) "[" %5.4f `adrrl' "," /*
			*/ _col(28) %5.4f `adrru' "]" /*
			*/ _col(37) %5.4f `aprr' /*
			*/ _col(45) "[" %5.4f `aprrl' "," /*
			*/ _col(54) %5.4f `aprru' "]" /*
			*/ _col(64) %5.4f `arr'
	di as text "{hline 8}{c BT}{hline 63}"
	di as text "Homogeneity test of driver RR estimates " /*
		*/ as result _col(60) "p = " %5.4f `dpchi'
	di as text "Homogeneity test of passenger RR estimates " /*
		*/ as result _col(60) "p = " %5.4f `ppchi'
	di as text "{hline 72}"

	/* now comes the second part of the big if/else loop, 
		showing results if there is only one stratum */
	}
	else 	{
		di
		local c1 = 73 - (8 + length("Pairs used = "))
		di as text "Double-pair method" _col(`c1') /*
			*/ "Pairs used = " as result %8.0g `prct'
		local levpc = `level'*100
		di as text "Relative Risk estimates" /*
		*/ _col(39)"Confidence interval level = " as result /*
		*/ %4.1f `levpc' " %"
		di as text "{hline 72}"
		di as text "dRR" _col(9)"[Conf. Interval]" /*
		*/ _col(27)"pRR" _col(35)"[Conf. Interval]" /*
		*/ _col(53)"RR"
		di as text "{hline 72}"
		di %5.4f as result `drr0' _col(9) "[" %5.4f `drrl0' "," /*
			*/ _col(18) %5.4f `drru0' "]" /*
			*/ _col(27) %5.4f `prr0' /*
			*/ _col(35) "[" %5.4f `prrl0' "," /*
			*/ _col(44) %5.4f `prru0' "]" /*
			*/ _col(53) %5.4f `rr0'
		di as text "{hline 72}"
	}

end