Dears,

I have separate outpatient and inpatient datasets both of which have multiple records per ID (URN_new) for a range variables such as outpatient appointments and inpatient admissions. I need to merge the two datasets so that I can do analyese involving both outpatient and inpatient service use. I thought I have to do m:m merge however there is a lot of information both in this forum and others discouraging m:m merging. Therefore, I tried joinby but I got too many records (280,071) in the joined dataset while the original datasets had only 45,750 and 29,285 records. Below are the a preview of the two datasets. I appreciate any help.

Thank you


[----------------------- Outpatient -----------------------
Code:
* Example generated by -dataex-. To install: ssc install dataex
clear
input long URN_new int AppointmentDate double AppointmentTime str38 AppointmentType float qdate
 601 20361      -1.8934242e+12 "Diabetes Review"           222
 601 20466      -1.8934242e+12 "Diabetes Review"           224
 601 20611       -1.893426e+12 "Diabetes Review"           225
 601 20670      -1.8934056e+12 "Diabetes Edu Group Review" 226
 601 20793       -1.893426e+12 "Diabetes Review"           227
 601 20947 -1893424800000.0002 "Diabetes Review"           229
 601 21101      -1.8934158e+12 "Diabetes Review"           231
 601 21101      -1.8934158e+12 "Diabetes Review"           231
 601 21283 -1893419699999.9998 "Diabetes Review"           233
 601 21283 -1893419699999.9998 "Diabetes Review"           233
 601 21402 -1893419699999.9998 "Diabetes Review"           234
 694 21097      -1.8934209e+12 "Diabetes Review"           231
 831 21349      -1.8934173e+12 "Diabetes New"              233
 831 21354      -1.8934083e+12 "Diabetes Phone Review"     233
 831 21361      -1.8934092e+12 "Diabetes Review"           233
 831 21361      -1.8934164e+12 "Diabetes Phone Review"     233
 831 21368      -1.8934182e+12 "Diabetes Review"           234
 831 21375      -1.8934272e+12 "Diabetes Phone Review"     234
 831 21382      -1.8934272e+12 "Diabetes Phone Review"     234
1252 21200      -1.8934182e+12 "Diabetes Review"           232
1252 21221      -1.8934173e+12 "Diabetes Review"           232
1252 21244        -1.89342e+12 "Diabetes Review"           232
1252 21251      -1.8934209e+12 "Diabetes Phone Review"     232
1252 21347      -1.8934227e+12 "Diabetes Review"           233
1252 21361      -1.8934227e+12 "Diabetes Review"           233
1252 21383      -1.8934164e+12 "Diabetes Review"           234
1252 21474      -1.8934236e+12 "Diabetes Review"           235
1252 21510      -1.8934254e+12 "Diabetes Review"           235
1252 21524      -1.8934254e+12 "Diabetes Review"           235
1252 21528      -1.8934182e+12 "Diabetes Review"           235
1777 21440      -1.8934254e+12 "Diabetes New"              234
1777 21468      -1.8934254e+12 "Diabetes Review"           235
1777 21479      -1.8934254e+12 "Diabetes Phone Review"     235
1777 21486      -1.8934182e+12 "Diabetes Phone Review"     235
1777 21531      -1.8934083e+12 "Diabetes Phone Review"     235
2135 21222      -1.8934092e+12 "Diabetes Review"           232
2135 21222      -1.8934074e+12 "Diabetes Review"           232
2135 21250       -1.893402e+12 "Diabetes Review"           232
2151 20380      -1.8934002e+12 "Diabetes Review"           223
2151 20464       -1.893408e+12 "Diabetes Review"           224
2151 20604       -1.893408e+12 "Diabetes Review"           225
2151 20695      -1.8934068e+12 "Diabetes Review"           226
2602 20590      -1.8934002e+12 "Diabetes Edu Review"       225
3174 20474      -1.8934188e+12 "Diabetes Edu Phone Review" 224
3174 20527       -1.893408e+12 "Diabetes New"              224
3174 20555       -1.893408e+12 "Diabetes New"              225
3174 20555       -1.893408e+12 "Diabetes New"              225
3174 20555       -1.893408e+12 "Diabetes New"              225
3174 20555       -1.893408e+12 "Diabetes New"              225
3205 21353       -1.893408e+12 "Diabetes New"              233
3205 21430       -1.893426e+12 "Diabetes New"              234
3205 21430      -1.8934182e+12 "Diabetes Edu Review"       234
3205 21465      -1.8934236e+12 "Diabetes Phone Review"     235
3205 21486      -1.8934236e+12 "Diabetes Phone Review"     235
3205 21486      -1.8934236e+12 "Diabetes Phone Review"     235
3517 20424 -1893416999999.9998 "Diabetes Review"           223
3595 20555       -1.893426e+12 "Diabetes New"              225
3595 20555       -1.893426e+12 "Diabetes New"              225
3595 20555      -1.8934164e+12 "Diabetes Edu Review"       225
3595 20555      -1.8934164e+12 "Diabetes Edu Review"       225
3595 20585      -1.8934074e+12 "Diabetes Edu New"          225
3595 20592      -1.8934056e+12 "Diabetes Edu Review"       225
3595 20626      -1.8934236e+12 "Diabetes Edu New"          225
3595 20627      -1.8934092e+12 "Diabetes Edu Review"       225
3595 20629      -1.8934074e+12 "Diabetes Edu Review"       225
3595 20634      -1.8934236e+12 "Diabetes Edu Review"       225
3595 20642      -1.8934236e+12 "Diabetes Edu Review"       226
3595 20647      -1.8934254e+12 "Diabetes Edu Phone Review" 226
3595 20650      -1.8934254e+12 "Diabetes Edu Phone Review" 226
3595 20653      -1.8934179e+12 "Diabetes Review"           226
3595 20654      -1.8934254e+12 "Diabetes Edu Phone Review" 226
3595 20657      -1.8934254e+12 "Diabetes Edu Phone Review" 226
3595 20744      -1.8934179e+12 "Diabetes Review"           227
3595 20759      -1.8934164e+12 "Diabetes Edu Review"       227
3595 20772      -1.8934233e+12 "Diabetes Review"           227
3595 20779       -1.893426e+12 "Diabetes Review"           227
3595 20863      -1.8934002e+12 "Diabetes Review"           228
3595 20870       -1.893426e+12 "Diabetes Review"           228
3595 20870      -1.8934182e+12 "Diabetes Edu Review"       228
3595 20878      -1.8934092e+12 "Diabetes Edu Review"       228
3595 20885      -1.8934092e+12 "Diabetes Edu Review"       228
3595 20892      -1.8934092e+12 "Diabetes Edu Review"       228
3595 20899      -1.8934092e+12 "Diabetes Edu Review"       228
3595 20906      -1.8934068e+12 "Diabetes Edu Review"       228
3595 20927      -1.8934236e+12 "Diabetes Edu Review"       229
3595 20937 -1893411599999.9998 "Diabetes Edu Phone Review" 229
3595 20943      -1.8934236e+12 "Diabetes Edu Review"       229
3595 20950 -1893414000000.0002 "Diabetes Edu Review"       229
3595 20957 -1893414000000.0002 "Diabetes Edu Review"       229
3595 20964      -1.8934182e+12 "Diabetes Edu Review"       229
3595 20971      -1.8934164e+12 "Diabetes Edu Review"       229
3595 20978      -1.8934164e+12 "Diabetes Edu Review"       229
3595 20985 -1893414000000.0002 "Diabetes Edu Review"       229
3595 20990      -1.8934236e+12 "Diabetes Edu Review"       229
3595 21013      -1.8934212e+12 "Diabetes Edu Review"       230
3595 21066 -1893419699999.9998 "Diabetes Review"           230
3595 21124      -1.8934164e+12 "Diabetes Edu Review"       231
3595 21132 -1893414000000.0002 "Diabetes Edu Review"       231
3595 21139      -1.8934164e+12 "Diabetes Edu Review"       231
3595 21146 -1893414000000.0002 "Diabetes Edu Review"       231
end
format %tddd-Mon-YY AppointmentDate
format %tchh:MM AppointmentTime
format %tq qdate
------------------ copy up to and including the previous line ------------------


][/----------------------- Inpatient -----------------------
Code:
* Example generated by -dataex-. To install: ssc install dataex
clear
input double URN_new int(AdmitDate DischargeDate LengthOfStay) double(ALOS TotalCost) float admissionGap str4 DRGcode long(AdmitSource PrincipalDiagnosis)
 578 21176 21201  25  4.38 6643.2588894   5 "U61B" 43  543
 578 20530 20530   1     1 797.86199336 646 "U60Z" 41  543
 578 21206 21218  12  4.38 6643.2588894 228 "U61B" 43  543
 578 21446 21452   6  4.38 6643.2588894   . "U61B" 43  543
 694 20855 20963 108 36.57 155508.65399  48 "A14A" 24   80
 694 21011 21012   1  1.43 1988.1031409  27 "I76B" 34 1638
 694 21039 21049  10  5.14 25622.725337   . "I15Z" 34 1638
 831 21258 21258   1  3.18 3823.5879914 138 "T61B"  3  490
 831 21396 21396   1  2.98 4573.7466533   5 "Z64A"  3  422
 831 21633 21634   1  1.47 1948.7668597   . "Z61B"  3  427
 831 21621 21621   1  1.61 1993.8071389  12 "I68B"  3  294
 831 21401 21405   4  2.48 4082.6048197 216 "K60B"  3   63
 831 21166 21166   1     .            .  92 "I79C"  3  308
1252 21495 21495   1  1.62 2357.5703669   . "L64A"  3  320
1538 20913 20922   9 23.33  62502.49338 262 "G02A"  7  123
1538 20478 20481   3  5.77 15350.511009   0 "I08C" 37 1988
1538 20746 20746   1   1.2 1593.6014406  12 "Z64B" 35 2203
1538 20786 20786   1     1 1765.2271336   2 "R63Z" 35 2219
1538 20636 20636   1     .            . 108 "L41Z" 56 1650
1538 20798 20807   9   4.8 9747.7298418   5 "Q60A" 35  365
1538 20481 20506  25  8.65  12021.43979 120 "I78A" 37 1988
1538 20758 20758   1     1 1765.2271336   2 "R63Z" 35 2219
1538 20760 20760   1   1.2 1593.6014406  12 "Z64B" 35 2203
1538 20774 20774   1   1.2 1593.6014406  12 "Z64B" 35 2203
1538 20744 20744   1     1 1765.2271336   2 "R63Z" 35 2219
1538 20626 20626   1  1.07 2216.9870465  10 "G48B" 16  273
1538 20812 20817   5  7.31 15632.140792  96 "G12B" 35  123
1538 21184 21184   1  1.35  1556.449996   . "G70C" 13 1203
1538 20772 20772   1     1 1765.2271336   2 "R63Z" 35 2219
1538 20788 20788   1   1.2 1593.6014406  10 "Z64B" 35 2203
1777 21372 21402  30 36.57 155508.65399   . "A14A"  3  188
2022 20340 20341   1  3.55 5716.6510998   4 "B71A" 35  665
2022 21705 21706   1  2.69 3876.6021616   . "E62B" 35 1005
2022 20739 20741   2  1.96 2867.4517282 388 "T62B" 35 1815
2022 20565 20566   1   4.4  6316.848872 173 "I71A" 35 1459
2022 20480 20482   2  6.97 11022.318042  25 "J69A" 35  148
2022 20360 20360   1  5.76 8706.9041793  13 "I76A" 13 1453
2022 20354 20354   1  5.73 11252.091114   6 "I12C" 37 1622
2022 20394 20394   1     1 1765.2271336  21 "R63Z" 35 2219
2022 21350 21350   1  1.79  3099.418148   3 "E63A" 29  644
2022 20436 20436   1     1 1765.2271336  21 "R63Z" 35 2219
2022 21129 21131   2  5.57 8662.3784051  65 "G70A" 35 1765
2022 21475 21475   1  1.05 2629.9460853 230 "J11B" 39  155
2022 20415 20415   1     1 1765.2271336  21 "R63Z" 35 2219
2022 20373 20373   1     1 1765.2271336  21 "R63Z" 35 2219
2022 21353 21357   4  6.21 10127.665202 118 "B81A" 29  671
2022 21196 21199   3  1.35  1556.449996  30 "G70C" 35 1765
2022 20457 20457   1     1 1765.2271336  23 "R63Z" 35 2219
2022 21229 21230   1 14.08  23560.38022 120 "I12B" 37 1622
2022 20345 20345   1     1 1765.2271336   9 "R63Z" 35 2219
2022 20507 20512   5   4.4  6316.848872  44 "I71A" 35 1456
2022 20556 20559   3  2.62 4184.1305553   6 "E67A" 35 1750
2022 20345 20346   1  6.24 6989.0168626  -1 "I64B" 35 1623
2151 20590 20597   7  6.03 17136.220585   . "H08A" 21 1260
2368 20418 20419   1   1.1 5817.8406347  18 "J07Z"  2  171
2368 20507 20507   1     1 1765.2271336  21 "R63Z" 35 2219
2368 21301 21301   1  1.05 1637.1067305   3 "Z40Z" 14 2165
2368 20465 20465   1     1 1765.2271336  21 "R63Z" 35 2219
2368 20486 20486   1     1 1765.2271336  21 "R63Z" 35 2219
2368 20437 20438   1   1.1 5817.8406347  27 "J07Z"  2  171
2368 21304 21306   2  1.32 7467.1064286   . "K05B"  5  309
2368 20528 20528   1     1 1765.2271336 773 "R63Z" 35 2219
2539 21257 21260   3  3.62 6159.4472067   . "B70C"  3  167
2662 21206 21209   3  4.36 9307.1230509   5 "K64A" 10  382
2662 21131 21131   1  2.47 3466.9572444  75 "G70B" 13 1196
2662 21214 21216   2  1.59  10095.88993   . "K06B"  5  382
2991 21169 21171   2  5.65  8372.365315   0 "E65A" 47 1041
2991 20916 20916   1  2.82 5079.7051888 253 "C63A" 29   72
2991 21183 21184   1  4.08   6578.26522 167 "F66A" 29  831
2991 21358 21370  12  6.29 13499.354549   . "E41B" 18 1041
2991 21171 21173   2  2.98 4573.7466533  10 "Z64A" 47 2242
2991 21351 21354   3  5.65  8372.365315   4 "E65A" 47 1041
3517 20636 20662  26  7.13  21543.20818   0 "F10A"  6  836
3517 20717 20720   3  2.04 3278.3468133   . "H64B" 16 1266
3517 20495 20495   1  1.05 1637.1067305 141 "Z40Z" 16 2169
3517 20662 20711  43 12.41 21350.892592   6 "B70A" 17  906
3620 21538 21538   1  1.23 1327.5986064   . "X60B" 13 1883
3620 21460 21460   1   1.3 1527.7909203  78 "D63B" 14 1011
4013 20510 20513   3  2.78  3764.075321 848 "E65B" 18 1041
4013 21548 21552   4  2.78  3764.075321   . "E65B" 28 1041
4013 21427 21427   1  1.02 1701.8407983  96 "C03B" 36  418
4013 21361 21361   1  1.02 1701.8407983  37 "C03B" 36  418
4013 21523 21523   1  1.02 1701.8407983  25 "C03B" 36  418
4013 21398 21398   1  1.02 1701.8407983  29 "C03B" 36  418
4232 21608 21609   1  9.23 15999.218575   . "B66A" 47  209
4232 21376 21382   6 12.74 29432.827589   2 "E02A" 28  144
4232 21456 21456   1     1 1765.2271336  26 "R63Z" 35 2219
4232 21594 21605  11  9.23 15999.218575   1 "B66A" 35  209
4232 21606 21608   2  9.23 15999.218575   0 "B66A" 47  209
4232 21434 21434   1     1 1765.2271336   1 "R63Z" 35 2219
4232 21435 21435   1     1 1765.2271336  19 "R63Z" 35 2219
4232 21405 21431  26  6.33 11153.920754   2 "K62A" 47  493
4232 21454 21454   1     1 1765.2271336   1 "R63Z" 35 2219
4232 21455 21455   1     1 1765.2271336   1 "R63Z" 35 2219
4232 21483 21483   1     1 1765.2271336   1 "R63Z" 35 2219
4232 21482 21482   1     1 1765.2271336   1 "R63Z" 35 2219
4232 21433 21433   1     1 1765.2271336   1 "R63Z" 35 2219
4232 21484 21484   1     1 1765.2271336 110 "R63Z" 35 2219
4232 21384 21388   4  8.12 13030.851629  17 "E71A" 47  144
4342 21327 21327   1  1.83 2208.8979991  35 "I72B"  3  304
end
format %tdnn/dd/CCYY AdmitDate
format %tdnn/dd/CCYY DischargeDate
label values AdmitSource AdmitSource
label def AdmitSource 2 "B&E", modify
label def AdmitSource 3 "BIRD", modify
label def AdmitSource 5 "BNE", modify
label def AdmitSource 6 "CARD", modify
label def AdmitSource 7 "COLO", modify
label def AdmitSource 10 "DEND", modify
label def AdmitSource 13 "EMER", modify
label def AdmitSource 14 "ENT", modify
label def AdmitSource 16 "GAST", modify
label def AdmitSource 17 "GERI", modify
label def AdmitSource 18 "GMAP", modify
label def AdmitSource 21 "HPB", modify
label def AdmitSource 24 "INFD", modify
label def AdmitSource 28 "MED3", modify
label def AdmitSource 29 "MED4", modify
label def AdmitSource 34 "NSUR", modify
label def AdmitSource 35 "OHU", modify
label def AdmitSource 36 "OPHT", modify
label def AdmitSource 37 "ORTH", modify
label def AdmitSource 39 "PLAS", modify
label def AdmitSource 41 "PSY", modify
label def AdmitSource 43 "PSYE", modify
label def AdmitSource 47 "RESP", modify
label def AdmitSource 56 "UROL", modify
label values PrincipalDiagnosis PrincipalDiagnosis
label def PrincipalDiagnosis 63 "B07", modify
label def PrincipalDiagnosis 72 "B30.9", modify
label def PrincipalDiagnosis 80 "B37.6", modify
label def PrincipalDiagnosis 123 "C18.7", modify
label def PrincipalDiagnosis 144 "C34.3", modify
label def PrincipalDiagnosis 148 "C43.4", modify
label def PrincipalDiagnosis 155 "C44.3", modify
label def PrincipalDiagnosis 167 "C49.3", modify
label def PrincipalDiagnosis 171 "C50.4", modify
label def PrincipalDiagnosis 188 "C71.2", modify
label def PrincipalDiagnosis 209 "C79.3", modify
label def PrincipalDiagnosis 273 "D12.0", modify
label def PrincipalDiagnosis 294 "D22.5", modify
label def PrincipalDiagnosis 304 "D32.0", modify
label def PrincipalDiagnosis 308 "D35.0", modify
label def PrincipalDiagnosis 309 "D35.1", modify
label def PrincipalDiagnosis 320 "D41.4", modify
label def PrincipalDiagnosis 365 "D70", modify
label def PrincipalDiagnosis 382 "E04.2", modify
label def PrincipalDiagnosis 418 "E11.33", modify
label def PrincipalDiagnosis 422 "E11.42", modify
label def PrincipalDiagnosis 427 "E11.64", modify
label def PrincipalDiagnosis 490 "E80.6", modify
label def PrincipalDiagnosis 493 "E83.5", modify
label def PrincipalDiagnosis 543 "F20.0", modify
label def PrincipalDiagnosis 644 "G47.32", modify
label def PrincipalDiagnosis 665 "G62.9", modify
label def PrincipalDiagnosis 671 "G72.0", modify
label def PrincipalDiagnosis 831 "I20.9", modify
label def PrincipalDiagnosis 836 "I21.4", modify
label def PrincipalDiagnosis 906 "I63.4", modify
label def PrincipalDiagnosis 1005 "J18.9", modify
label def PrincipalDiagnosis 1011 "J32.0", modify
label def PrincipalDiagnosis 1041 "J44.0", modify
label def PrincipalDiagnosis 1196 "K57.30", modify
label def PrincipalDiagnosis 1203 "K59.0", modify
label def PrincipalDiagnosis 1260 "K80.00", modify
label def PrincipalDiagnosis 1266 "K80.40", modify
label def PrincipalDiagnosis 1453 "M25.46", modify
label def PrincipalDiagnosis 1456 "M25.53", modify
label def PrincipalDiagnosis 1459 "M25.57", modify
label def PrincipalDiagnosis 1622 "M87.15", modify
label def PrincipalDiagnosis 1623 "M87.16", modify
label def PrincipalDiagnosis 1638 "M95.2", modify
label def PrincipalDiagnosis 1650 "N13.1", modify
label def PrincipalDiagnosis 1750 "R06.0", modify
label def PrincipalDiagnosis 1765 "R11", modify
label def PrincipalDiagnosis 1815 "R50.9", modify
label def PrincipalDiagnosis 1883 "S19.9", modify
label def PrincipalDiagnosis 1988 "S72.2", modify
label def PrincipalDiagnosis 2165 "Z01.8", modify
label def PrincipalDiagnosis 2169 "Z08.0", modify
label def PrincipalDiagnosis 2203 "Z45.1", modify
label def PrincipalDiagnosis 2219 "Z51.1", modify
label def PrincipalDiagnosis 2242 "Z75.2", modify
------------------ copy up to and including the previous line ------------------

Listed 100 out of 45750 observations
Use the count() option to list more

.
end of do-file

.
]