World J Nephrol Urol

World Journal of Nephrology and Urology, ISSN 1927-1239 print, 1927-1247 online, Open Access

Article copyright, the authors; Journal compilation copyright, World J Nephrol Urol and Elmer Press Inc

Journal website https://www.wjnu.org

Original Article

Volume 11, Number 1, June 2022, pages 10-17

Opioid Prescribing for Kidney Stone Formers Undergoing Stone Removal

**Table 1.** Means With Standard Deviations for Demographic Characteristics, Comorbidities, and Surgical Procedures of the Three Cohorts
Patient characteristic	Total (n = 75)	Cystinuric stone formers (n = 25)	Non-cystine recurrent stone formers (n = 25)	Non-cystine first-time stone formers (n = 25)	P-value
^aRace data available for 24/25 for first-time stone formers. BMI: body mass index.
Gender					1.0
Male	42 (56%)	14 (56%)	14 (56%)	14 (56%)
Female	33 (44%)	11 (44%)	11 (44%)	11 (44%)
Age (years)	35.4 ± 15.4	34.7 ± 16.7	35.6 ± 14.5	35.8 ± 15.4	0.97
BMI (kg/m²)	30.6 ± 8.6	30.9 ± 9.4	30.5 ± 8.3	30.4 ± 8.5	0.98
Race^a					0.70
White	60 (81.1%)	21 (84%)	21 (84%)	18 (75%)
Non-white	14 (18.9%)	4 (16%)	4 (16%)	6 (25%)
Married	32 (42.7%)	11 (44%)	8 (32%)	13 (52%)	0.40
Not married	43 (57.3%)	14 (56%)	17 (68%)	12 (48%)
Zip code adjusted income (US dollars)	49,524.3 ± 19,935.3	54,016.0 ± 23,694.8	47,187.2 ± 18,835.1	47,455.8 ± 16,856.1	0.41
Ureteroscopic stone removal	59 (78.7%)	21 (84%)	18 (72%)	20 (80%)	0.57
Percutaneous nephrolithotomy	16 (31.3%)	4 (16%)	7 (28%)	5 (20%)
Medical comorbidities (number)	3.7 ± 3.7	2.4 ± 2.3	5.6 ± 4.9	2.9 ± 2.4	0.003
Hypertension	16 (21.3%)	2 (8%)	8 (32%)	6 (24%)	0.11
Diabetes mellitus	8 (10.7%)	0 (0%)	5 (20%)	3 (12%)	0.09
Obesity	35 (46.7%)	13 (52%)	11 (44%)	11 (44%)	0.81
Chronic kidney disease	5 (6.7%)	2 (8%)	1 (4%)	2 (8%)	1.0
Other endocrine disorders	4 (5.3%)	1 (4%)	3 (12%)	0 (0%)	0.32
Stroke	0 (0%)	0 (0%)	0 (0%)	0 (0%)	1.0
Number of UAB stone removing procedures	3.7 ± 3.4	4.0 ± 3.8	4.9 ± 3.6	2.0 ± 1.6	0.006
Number of UAB non-urology procedures	0.2 ± 0.5	0.2 ± 0.4	0.1 ± 0.4	0.3 ± 0.7	0.28

Table 1. Means With Standard Deviations for Demographic Characteristics, Comorbidities, and Surgical Procedures of the Three Cohorts

Patient characteristic

Total (n = 75)

Cystinuric stone formers (n = 25)

Non-cystine recurrent stone formers (n = 25)

Non-cystine first-time stone formers (n = 25)

P-value

^aRace data available for 24/25 for first-time stone formers. BMI: body mass index.

Gender

1.0

Male

42 (56%)

14 (56%)

Female

33 (44%)

11 (44%)

Age (years)

35.4 ± 15.4

34.7 ± 16.7

35.6 ± 14.5

35.8 ± 15.4

0.97

BMI (kg/m²)

30.6 ± 8.6

30.9 ± 9.4

30.5 ± 8.3

30.4 ± 8.5

0.98

Race^a

0.70

White

60 (81.1%)

21 (84%)

18 (75%)

Non-white

14 (18.9%)

4 (16%)

6 (25%)

Married

32 (42.7%)

11 (44%)

8 (32%)

13 (52%)

0.40

Not married

43 (57.3%)

14 (56%)

17 (68%)

12 (48%)

Zip code adjusted income (US dollars)

49,524.3 ± 19,935.3

54,016.0 ± 23,694.8

47,187.2 ± 18,835.1

47,455.8 ± 16,856.1

0.41

Ureteroscopic stone removal

59 (78.7%)

21 (84%)

18 (72%)

20 (80%)

0.57

Percutaneous nephrolithotomy

16 (31.3%)

4 (16%)

7 (28%)

5 (20%)

Medical comorbidities (number)

3.7 ± 3.7

2.4 ± 2.3

5.6 ± 4.9

2.9 ± 2.4

0.003

Hypertension

16 (21.3%)

2 (8%)

8 (32%)

6 (24%)

0.11

Diabetes mellitus

8 (10.7%)

0 (0%)

5 (20%)

3 (12%)

0.09

Obesity

35 (46.7%)

13 (52%)

11 (44%)

0.81

Chronic kidney disease

5 (6.7%)

2 (8%)

1 (4%)

2 (8%)

1.0

Other endocrine disorders

4 (5.3%)

1 (4%)

3 (12%)

0 (0%)

0.32

Stroke

0 (0%)

1.0

Number of UAB stone removing procedures

3.7 ± 3.4

4.0 ± 3.8

4.9 ± 3.6

2.0 ± 1.6

0.006

Number of UAB non-urology procedures

0.2 ± 0.5

0.2 ± 0.4

0.1 ± 0.4

0.3 ± 0.7

0.28

**Table 2.** Means and Standard Deviations for UAB Hospital and Discharge Opioid Utilization
	Total (n = 75)	Cystinuric stone formers (n = 25)	Non-cystine recurrent stone formers (n = 25)	Non-cystine first-time stone formers (n = 25)	P-value
^aData available for n = 61 total; n = 21 for cystinuric stone formers and first-time stone formers, n = 19 for recurrent stone formers. MME: morphine milligram equivalent.
UAB hospital opioid utilization (MME/stay)
Intraoperative MME^a	17.6 ± 7.3	19.7 ± 6.2	15.9 ± 8.6	17.0 ± 6.9	0.25
Inpatient MME	47.9 ± 85.6	42.1 ± 90.9	56.6 ± 83.6	45.0 ± 84.9	0.82
UAB opioid discharge prescription amounts (MME/patient/discharge)
2013 - 2016	216.7 ± 135.9	236.4 ± 158.4	190 ± 139.9	230.6 ± 111.1
2017 - 2019	124.2 ± 106.1	162.8 ± 131.3	109.2 ± 81.5	100.2 ± 92.3
P-value	0.002	0.24	0.10	0.010

Table 2. Means and Standard Deviations for UAB Hospital and Discharge Opioid Utilization

Total (n = 75)

Cystinuric stone formers (n = 25)

Non-cystine recurrent stone formers (n = 25)

Non-cystine first-time stone formers (n = 25)

P-value

^aData available for n = 61 total; n = 21 for cystinuric stone formers and first-time stone formers, n = 19 for recurrent stone formers. MME: morphine milligram equivalent.

UAB hospital opioid utilization (MME/stay)

Intraoperative MME^a

17.6 ± 7.3

19.7 ± 6.2

15.9 ± 8.6

17.0 ± 6.9

0.25

Inpatient MME

47.9 ± 85.6

42.1 ± 90.9

56.6 ± 83.6

45.0 ± 84.9

0.82

UAB opioid discharge prescription amounts (MME/patient/discharge)

2013 - 2016

216.7 ± 135.9

236.4 ± 158.4

190 ± 139.9

230.6 ± 111.1

2017 - 2019

124.2 ± 106.1

162.8 ± 131.3

109.2 ± 81.5

100.2 ± 92.3

P-value

0.002

0.24

0.10

0.010

**Table 3.** Means and Standard Deviations for Number of Discrete Providers and MMEs From PDMP (Provider/MME/Patient)
	Total (n = 75)	Cystinuric stone formers (n = 25)	Non-cystine recurrent stone formers (n = 25)	Non-cystine first-time stone formers (n = 25)	P-value
Total opioid exposure over 6 years including high opioid utilizing individuals (> 470,000 MME over 6 years) found in each cohort. Total opioid exposure over 6 years excluding high opioid utilizing individuals: ^a8,699.0 ± 23,400.7; ^b10,623.1 ± 24,803.1 ; ^c10,303.2 ± 27,726.7 ; ^d5,170.6 ± 16,938.1 ; ^e0.67. MMEs: morphine milligram equivalents; PDMP: prescription drug monitoring program.
Discrete providers	7.9 ± 7.3	8.7 ± 8.1	7.8 ± 7.2	7.2 ± 6.7	0.76
Non-UAB providers	7.2 ± 7.2	7.8 ± 8.0	7.2 ± 7.1	6.4 ± 6.6	0.79
MMEs exposure within 180 days of stone removal procedure	3,377.6 ± 11,932.7	3,117.8 ± 10,238.3	3,406.3 ± 12,009.3	3,608.7 ± 13,779.0	0.99
Total opioid exposure over 6 years	27,987.8 ± 97,891.2^a	29,951.8 ± 99,647.3^b	30,116.7 ± 102,718.4^c	23,894.8 ± 95,077.6^d	0.97^e

Table 3. Means and Standard Deviations for Number of Discrete Providers and MMEs From PDMP (Provider/MME/Patient)

Total (n = 75)

Cystinuric stone formers (n = 25)

Non-cystine recurrent stone formers (n = 25)

Non-cystine first-time stone formers (n = 25)

P-value

Total opioid exposure over 6 years including high opioid utilizing individuals (> 470,000 MME over 6 years) found in each cohort. Total opioid exposure over 6 years excluding high opioid utilizing individuals: ^a8,699.0 ± 23,400.7; ^b10,623.1 ± 24,803.1 ; ^c10,303.2 ± 27,726.7 ; ^d5,170.6 ± 16,938.1 ; ^e0.67. MMEs: morphine milligram equivalents; PDMP: prescription drug monitoring program.

Discrete providers

7.9 ± 7.3

8.7 ± 8.1

7.8 ± 7.2

7.2 ± 6.7

0.76

Non-UAB providers

7.2 ± 7.2

7.8 ± 8.0

7.2 ± 7.1

6.4 ± 6.6

0.79

MMEs exposure within 180 days of stone removal procedure

3,377.6 ± 11,932.7

3,117.8 ± 10,238.3

3,406.3 ± 12,009.3

3,608.7 ± 13,779.0

0.99

Total opioid exposure over 6 years

27,987.8 ± 97,891.2^a

29,951.8 ± 99,647.3^b

30,116.7 ± 102,718.4^c

23,894.8 ± 95,077.6^d

0.97^e

**Table 4.** Mean and Standard Deviation for Provider Prescribing Habits by Specialty and Prescribing Provider Distribution From PDMP
Provider specialty	Total (n = 1,596 prescriptions from n = 75 patients)	Cystinuric stone formers (n = 660 prescriptions from n = 25 patients)	Non-cystine recurrent stone formers (n = 597 prescriptions from n = 25 patients)	Non-cystine first-time stone formers (n = 339 prescriptions from n = 25 patients)	P-value
^aA significant difference between cystinuric and recurrent stone formers. ^bA significant difference between cystinuric and first-time stone formers. ^cA difference between recurrent and first-time stone formers. MME: morphine milligram equivalent; PDMP: prescription drug monitoring program.
Pain management
MME	2,616.9 ± 2399.8	3,147.6 ± 2697.7	2,300.7 ± 2,166.4	576.7 ± 233.5	< 0.001^{a, b}
Prescriptions	420 (26.3%)	169 (25.6%)	245 (41.0%)	6 (1.8%)	0.001
Urology
MME	216.1 ± 173.7	230.6 ± 182.4	209.2 ± 180.3	184.6 ± 108.8	0.29
Prescriptions	295 (18.4%)	141 (21.4%)	114 (19.1%)	40 (11.8%)	0.001
Emergency medicine
MME	138.1 ± 86.1	152.4 ± 87.8	132.5 ± 77.8	127 ± 90.9	0.38
Prescriptions	117 (7.3%)	43 (6.5%)	34 (5.7%)	40 (11.8%)	0.002
Primary care providers
MME	1,623.0 ± 2,855.2	671.2 ± 796.2	1,248.9 ± 1,472.4	3,062.5 ± 4,217.0	< 0.001^b,c
Prescriptions	510 (32.0%)	238 (36.1%)	91 (15.2%)	181 (53.4%)	< 0.001
Other surgical specialties
MME	402.8 ± 1,078.2	164.8 ± 105.8	439.3 ± 413.1	426.7 ± 1528.7	0.59
Prescriptions	104 (6.5%)	18 (2.7%)	37 (6.2%)	49 (14.4%)	< 0.001
Other medical specialties
MME	497.2 ± 666.9	186.3 ± 116.5	720.8 ± 814.3	238.7 ± 167.8	0.034a
Prescriptions	44 (2.8%)	13 (2.0%)	25 (4.2%)	6 (1.8%)	0.026
Dental
MME	148.9 ± 68.0	138.8 ± 59.2	172.6 ± 72.0	103.2 ± 33.0	0.023^c
Prescriptions	35 (2.2%)	4 (0.6%)	21 (3.5%)	10 (2.9%)	0.001
Unknown
MME	274.6 ± 227.8	328.2 ± 292.3	218.5 ± 124.4	254.2 ± 168.4	0.15
Prescriptions	71 (4.4%)	34 (5.2%)	30 (5.1%)	7 (2.1%)	0.056

Table 4. Mean and Standard Deviation for Provider Prescribing Habits by Specialty and Prescribing Provider Distribution From PDMP

Provider specialty

Total (n = 1,596 prescriptions from n = 75 patients)

Cystinuric stone formers (n = 660 prescriptions from n = 25 patients)

Non-cystine recurrent stone formers (n = 597 prescriptions from n = 25 patients)

Non-cystine first-time stone formers (n = 339 prescriptions from n = 25 patients)

P-value

^aA significant difference between cystinuric and recurrent stone formers. ^bA significant difference between cystinuric and first-time stone formers. ^cA difference between recurrent and first-time stone formers. MME: morphine milligram equivalent; PDMP: prescription drug monitoring program.

Pain management

MME

2,616.9 ± 2399.8

3,147.6 ± 2697.7

2,300.7 ± 2,166.4

576.7 ± 233.5

< 0.001^{a, b}

Prescriptions

420 (26.3%)

169 (25.6%)

245 (41.0%)

6 (1.8%)

0.001

Urology

MME

216.1 ± 173.7

230.6 ± 182.4

209.2 ± 180.3

184.6 ± 108.8

0.29

Prescriptions

295 (18.4%)

141 (21.4%)

114 (19.1%)

40 (11.8%)

0.001

Emergency medicine

MME

138.1 ± 86.1

152.4 ± 87.8

132.5 ± 77.8

127 ± 90.9

0.38

Prescriptions

117 (7.3%)

43 (6.5%)

34 (5.7%)

40 (11.8%)

0.002

Primary care providers

MME

1,623.0 ± 2,855.2

671.2 ± 796.2

1,248.9 ± 1,472.4

3,062.5 ± 4,217.0

< 0.001^b,c

Prescriptions

510 (32.0%)

238 (36.1%)

91 (15.2%)

181 (53.4%)

< 0.001

Other surgical specialties

MME

402.8 ± 1,078.2

164.8 ± 105.8

439.3 ± 413.1

426.7 ± 1528.7

0.59

Prescriptions

104 (6.5%)

18 (2.7%)

37 (6.2%)

49 (14.4%)

< 0.001

Other medical specialties

MME

497.2 ± 666.9

186.3 ± 116.5

720.8 ± 814.3

238.7 ± 167.8

0.034a

Prescriptions

44 (2.8%)

13 (2.0%)

25 (4.2%)

6 (1.8%)

0.026

Dental

MME

148.9 ± 68.0

138.8 ± 59.2

172.6 ± 72.0

103.2 ± 33.0

0.023^c

Prescriptions

35 (2.2%)

4 (0.6%)

21 (3.5%)

10 (2.9%)

0.001

Unknown

MME

274.6 ± 227.8

328.2 ± 292.3

218.5 ± 124.4

254.2 ± 168.4

0.15

Prescriptions

71 (4.4%)

34 (5.2%)

30 (5.1%)

7 (2.1%)

0.056

**Table 5.** Mean and Standard Deviation for Total Opioid Utilization by Year, Average Prescription MME, and Average Number of Opioid Prescriptions by Year, All From PDMP
	Cystinuric stone formers (n = 25)	Non-cystine recurrent stone formers (n = 25)	Non-cystine first-time stone formers (n = 25)	Total (n = 75)
MME: morphine milligram equivalent; PDMP: prescription drug monitoring program.
Total opioid utilization (MME/year/person)
2013 - 2016	3,963.4 ± 13,010.0	5,014.5 ± 17,586.1	5,766.6 ± 25,919.8	4,914.8 ± 19,329.9
2017 - 2019	5,786.1 ± 19,400.3	4,241.1 ± 13,566.4	1,262.6 ± 3,799.2	3,858.5 ± 13,763.2
P-value	0.19	0.41	0.38	0.52
Average prescription MME (MME/prescription/time period)
2013 - 2016	269.6 ± 647.6	342.7 ± 758.9	419.2 ± 1,483.8	343.8 ± 1,020.1
2017 - 2019	450.9 ± 1,040.9	337.7 ± 765.8	316.4 ± 793.3	368.3 ± 865.6
P-value	0.05	0.92	0.52	0.70
Total number of opioid prescriptions (prescription/year)
2013 - 2016	4.1 ± 6.4	4.0 ± 6.6	2.2 ± 4.5	3.4 ± 5.9
2017 - 2019	4.7 ± 6.7	3.5 ± 6.3	2.5 ± 2.9	3.6 ± 5.6
P-value	0.52	0.49	0.78	0.80

Table 5. Mean and Standard Deviation for Total Opioid Utilization by Year, Average Prescription MME, and Average Number of Opioid Prescriptions by Year, All From PDMP

Cystinuric stone formers (n = 25)

Non-cystine recurrent stone formers (n = 25)

Non-cystine first-time stone formers (n = 25)

Total (n = 75)

MME: morphine milligram equivalent; PDMP: prescription drug monitoring program.

Total opioid utilization (MME/year/person)

2013 - 2016

3,963.4 ± 13,010.0

5,014.5 ± 17,586.1

5,766.6 ± 25,919.8

4,914.8 ± 19,329.9

2017 - 2019

5,786.1 ± 19,400.3

4,241.1 ± 13,566.4

1,262.6 ± 3,799.2

3,858.5 ± 13,763.2

P-value

0.19

0.41

0.38

0.52

Average prescription MME (MME/prescription/time period)

2013 - 2016

269.6 ± 647.6

342.7 ± 758.9

419.2 ± 1,483.8

343.8 ± 1,020.1

2017 - 2019

450.9 ± 1,040.9

337.7 ± 765.8

316.4 ± 793.3

368.3 ± 865.6

P-value

0.05

0.92

0.52

0.70

Total number of opioid prescriptions (prescription/year)

2013 - 2016

4.1 ± 6.4

4.0 ± 6.6

2.2 ± 4.5

3.4 ± 5.9

2017 - 2019

4.7 ± 6.7

3.5 ± 6.3

2.5 ± 2.9

3.6 ± 5.6

P-value

0.52

0.49

0.78

0.80