The economic burden of treatment failure amongst patients with irritable bowel syndrome with constipation or chronic constipation: a retrospective analysis of a Medicaid population

Figures & data

Figure 1. Sample Selection Flowchart.

Table 1. Frequency of treatment failure.

Indicator of treatment failure*	IBS-C				CC
	12 months following the index date		Entire observation period†		12 months following the index date		Entire observation period^†
	% of failures (n = 1311)	% of total (n = 2830)	% of failures (n = 2149)	% of total (n = 2830)	% of failures (n = 4798)	% of total (n = 8745)	% of failures (n = 6894)	% of total (n = 8745)
Any indicator of treatment failure	100.0%	46.3%	100.0%	75.9%	100.0%	54.9%	100.0%	78.7%
Therapy augmentation with another constipation/IBS-C treatment	17.0%	7.9%	11.5%	8.7%	13.1%	7.2%	9.1%	7.2%
Switch from one constipation/IBS-C treatment to another	74.0%	34.3%	90.4%	68.7%	88.4%	48.5%	94.8%	74.6%
IP or ED admission related to constipation or IBS	24.0%	11.1%	27.8%	21.1%	14.0%	7.7%	20.7%	16.3%
Diagnoses indicating treatment failure	3.7%	1.7%	5.9%	4.5%	3.6%	2.0%	8.3%	4.6%
Procedures indicating treatment failure	10.9%	5.1%	14.6%	11.1%	7.0%	3.9%	9.6%	7.6%
Prescription for more aggressive therapies	8.9%	4.1%	13.2%	10.0%	4.5%	2.4%	6.0%	4.7%

IBS-C, irritable bowel syndrome with constipation; CC, chronic constipation; CCI, Charlson comorbidity index; IP, inpatient; ED, emergency department.

*Categories are not mutually exclusive.

†The median observation time was 4.9 years for both IBS-C and CC samples.

Table 2. Patient baseline characteristics.

	IBS-C (n = 2830)			CC (n = 8745)
	With treatment failure	Without treatment failure	p Value	With treatment failure	Without treatment failure	p Value
Number of Patients	1311	1519		4798	3947
Demographics
Age at treatment index date, mean ± SD	51.3 ± 16.2	51.1 ± 16.3	0.715	57.3 ± 18.0	57.1 ± 18.3	0.797
Female, n (%)	1124 (85.7)	1329 (87.5)	0.171	3299 (68.8)	2786 (70.6)	0.065
Ethnicity, n (%)
Caucasian	1062 (81.0)	1299 (85.5)	0.001*	3528 (73.5)	2869 (72.7)	0.376
African American	192 (14.6)	172 (11.3)	0.008*	1096 (22.8)	930 (23.6)	0.428
Asian	0 (0.0)	1 (0.1)	0.353	9 (0.2)	2 (0.1)	0.072
Hispanic	3 (0.2)	4 (0.3)	0.854	21 (0.4)	22 (0.6)	0.426
Other	54 (4.1)	43 (2.8)	0.060	144 (3.0)	124 (3.1)	0.705
CCI, mean ± SD	2.3 ± 2.3	2.3 ± 2.4	0.984	2.6 ± 2.6	2.4 ± 2.6	0.001*
Presence of other physical and mental comorbid conditions†, n (%)
Chronic pulmonary disease	729 (55.6)	791 (52.1)	0.060	2226 (46.4)	1780 (45.1)	0.226
Hypertension (uncomplicated and complicated)	669 (51.0)	777 (51.2)	0.948	2745 (57.2)	2204 (55.8)	0.198
Depression	639 (48.7)	736 (48.5)	0.878	1383 (28.8)	1080 (27.4)	0.130
Psychoses	587 (44.8)	662 (43.6)	0.524	1442 (30.1)	1144 (29.0)	0.275
Fluid and electrolyte disorders	360 (27.5)	396 (26.1)	0.405	988 (20.6)	796 (20.2)	0.624
Diabetes, complicated	116 (8.8)	137 (9.0)	0.874	721 (15.0)	513 (13.0)	0.007*
Diabetes, uncomplicated	294 (22.4)	361 (23.8)	0.399	1429 (29.8)	1088 (27.6)	0.023
Deficiency anemias	272 (20.7)	300 (19.7)	0.510	858 (17.9)	692 (17.5)	0.670
Rheumatoid arthritis/collagen vascular diseases	252 (19.2)	312 (20.5)	0.382	641 (13.4)	539 (13.7)	0.687
Misc. neurological disorders	262 (20.0)	274 (18.0)	0.188	856 (17.8)	714 (18.1)	0.763
Hypothyroidism	235 (17.9)	259 (17.1)	0.541	572 (11.9)	469 (11.9)	0.955
Peptic ulcer disease excluding bleeding	218 (16.6)	240 (15.8)	0.551	407 (8.5)	329 (8.3)	0.805
Valvular disease	210 (16.0)	231 (15.2)	0.553	763 (15.9)	568 (14.4)	0.050
Peripheral vascular disorders	217 (16.6)	213 (14.0)	0.062	875 (18.2)	689 (17.5)	0.343
Obesity	180 (13.7)	238 (15.7)	0.147	508 (10.6)	421 (10.7)	0.906
Congestive heart failure	187 (14.3)	193 (12.7)	0.225	937 (19.5)	766 (19.4)	0.886
Drug abuse	165 (12.6)	154 (10.1)	0.040*	371 (7.7)	253 (6.4)	0.017*
Solid tumor without metastasis	129 (9.8)	177 (11.7)	0.122	535 (11.2)	414 (10.5)	0.322
Alcohol abuse	78 (5.9)	98 (6.5)	0.581	362 (7.5)	249 (6.3)	0.024*
Renal failure	52 (4.0)	64 (4.2)	0.741	353 (7.4)	217 (5.5)	<0.001*
Baseline Healthcare resource utilization, Mean ± SD
IP admissions	0.4 ± 0.9	0.4 ± 0.8	0.163	0.5 ± 1.0	0.4 ± 0.9	<0.001*
IP days	2.1 ± 5.3	1.7 ± 4.6	0.126	4.3 ± 9.9	3.5 ± 9.1	<0.001*
ED admissions	1.7 ± 3.1	1.4 ± 2.6	0.015*	1.0 ± 1.9	0.8 ± 1.7	<0.001*
OP visits	13.5 ± 8.9	12.2 ± 8.2	<0.001*	9.9 ± 8.1	9.4 ± 7.9	0.0003*
Baseline Healthcare Costs, Mean ± SD	8616 ± 8059	7452 ± 7620	<0.001*	7971 ± 10,795	7031 ± 8169	<0.001*
Medical costs	5235 ± 6137	4405 ± 6094	<0.001*	5112 ± 7343	4521 ± 6901	<0.001*
Pharmacy costs	3381 ± 4201	3047 ± 3415	0.020*	2859 ± 7026	2509 ± 3279	0.003*

IBS-C, irritable bowel syndrome with constipation; CC, chronic constipation; IP, inpatient; ED, emergency department; OP, outpatient.

*p Value <0.05.

†Only comorbid conditions with at least 5% prevalence in both groups are shown.

Table 3. Comparison of healthcare resource utilization between patients with and without treatment failure.

	IBS-C			CC
	Incidence per patient year		Adjusted IRR† IRR (95% CI)	Incidence per patient year		Adjusted IRR† IRR (95% CI)
	With treatment failure	Without treatment failure		With treatment failure	Without treatment failure
All patients
IP admissions	0.92	0.52	1.66 (1.51–1.81)*	0.98	0.62	1.52 (1.44–1.59)*
IP days	4.77	2.53	1.75 (1.68–1.82)*	5.76	3.58	1.54 (1.51–1.57)*
OP visits	28.07	23.13	1.16 (1.14–1.17)*	23.00	19.91	1.12 (1.11–1.13)*
ED visits	3.42	2.6	1.27 (1.22–1.33)*	2.34	1.7	1.35 (1.31–1.39)*
HCV	13.23	10.56	1.23 (1.20–1.26)*	17.83	16.18	1.09 (1.08–1.10)*
LTC days	1.12	0.68	1.67 (1.54–1.81)*	1.54	0.73	2.05 (2.05–2.05)*
MHF days	11.04	8.71	1.16 (1.13–1.19)*	8.64	8.17	1.00 (0.99–1.02)
OTC treatment sub-group
IP admissions	0.95	0.55	1.61 (1.43–1.80)*	1.02	0.6	1.65 (1.56–1.74)*
IP days	4.86	2.67	1.72 (1.63–1.81)*	6.02	3.53	1.67 (1.63–1.71)*
OP visits	28.07	23.46	1.14 (1.12–1.16)*	23.12	19.57	1.13 (1.12–1.14)*
ED visits	3.53	2.62	1.28 (1.21–1.35)*	2.48	1.71	1.39 (1.34–1.44)*
HCV	14.44	11.08	1.24 (1.21–1.28)*	18.15	16.16	1.09 (1.08–1.11)*
LTC days	0.9	0.94	NA	1.59	0.9	NA
MHF days	11.97	9.21	1.25 (1.22–1.29)*	9.26	8.37	1.05 (1.04–1.07)*
Prescription treatment Sub-group
IP admissions	0.87	0.47	1.80 (1.56–2.09)*	1.02	0.63	1.52 (1.38–1.66)*
IP days	4.61	2.33	1.87 (1.75–2.00)*	6.1	3.47	1.64 (1.58–1.71)*
OP visits	28.14	22.83	1.17 (1.15–1.20)*	23.66	20.88	1.10 (1.08–1.12)*
ED visits	3.2	2.7	1.16 (1.08–1.24)*	2.29	1.51	1.53 (1.44–1.62)*
HCV	11.71	9.87	1.28 (1.23–1.32)*	18.02	16.05	1.09 (1.07–1.12)*
LTC days	1.45	0.35	NA	1.49	0.24	NA
MHF days	8.98	8.15	1.04 (1.00–1.09)*	7.38	6.66	1.20 (1.16–1.23)*

IBS-C, irritable bowel syndrome with constipation; CC, chronic constipation; IP, inpatient; OP, outpatient; ED, emergency department; HCV, home care visits; LTC, long-term care; MHF, mental health facility.

*p Value <0.05.

†An IRR >1 indicates that patients with treatment failure had a higher incidence rate of that healthcare resource during the study period. Multivariate regression models adjusted for potential confounding factors, including age, gender, ethnicity, CCI, comorbidities with at least 5% prevalence in both groups and a statistically significant difference, and baseline HRU.

Table 4. Comparison of healthcare costs between patients with and without treatment failure.

	IBS-C			CC
	Patients with treatment failure	Patients without treatment failure	Adjusted^† incremental costs associated with treatment failure	Patients with treatment failure,	Patients without treatment failure,	Adjusted incremental costs associated with treatment failure†
	Mean ± SD	Mean ± SD		Mean ± SD	Mean ± SD
	[A]	[B]	∼[A] − [B]	[A]	[B]	∼[A] − [B]
All patients
Total medical costs ($)	11,021 ± 11,447	7497 ± 8994	3106*	11,503 ± 14,667	9000 ± 12,326	1996*
Typical medical costs	6431 ± 8685	4138 ± 6071	2091*	5756 ± 11,029	4010 ± 8895	1464*
IP costs	2179 ± 5930	1007 ± 3772	1080*	2575 ± 8892	1534 ± 7255	843*
OP costs	3352 ± 3821	2547 ± 3311	706*	2635 ± 3708	2057 ± 3132	510*
ED costs	900 ± 2167	584 ± 1641	306*	545 ± 1462	419 ± 1312	112*
Other medical costs	4590 ± 7659	3359 ± 6215	1014*	5747 ± 8925	4990 ± 8316	532*
HCV costs	2911 ± 6233	2135 ± 5163	684*	4151 ± 7927	3661 ± 7045	370*
LTC costs	46 ± 285	23 ± 247	21*	71 ± 488	29 ± 282	37*
MHF costs	1107 ± 4156	793 ± 2618	251	790 ± 3030	806 ± 3587	−56
Other medical service costs	525 ± 1466	409 ± 1464	58	735 ± 2460	494 ± 1708	180*
Pharmacy costs ($)	7864 ± 8972	6400 ± 7655	1247*	7114 ± 15,040	5929 ± 7664	982*
Constipation/IBS-C treatment costs	171 ± 285	105 ± 274	66*	127 ± 246	86 ± 147	43*
Prescription	97 ± 267	71 ± 272	28*	56 ± 183	42 ± 145	17*
OTC	74 ± 97	34 ± 63	38*	72 ± 168	44 ± 64	27*
Other drug costs	7693 ± 8900	6295 ± 7596	1181*	6986 ± 15,016	5844 ± 7642	939*
Total costs ($)	18,886 ± 15,835	13,897 ± 13,479	4353*	18,617 ± 22,837	14,929 ± 15,861	2978*
OTC treatment sub-group
Total medical costs ($)	11,590 ± 11,752	7711 ± 9088	3415*	12,102 ± 15,375	9159 ± 12,610	2409*
Typical medical costs	6688 ± 9270	4203 ± 6276	2245*	6091 ± 11,651	4022 ± 9165	1745*
IP costs	2313 ± 6280	1122 ± 4193	1085*	2801 ± 9363	1640 ± 7739	977*
OP costs	3397 ± 3921	2519 ± 3378	779*	2706 ± 4002	1957 ± 2896	634*
ED costs	979 ± 2390	562 ± 1372	380*	584 ± 1510	425 ± 1355	134*
Other medical costs	4901 ± 7267	3509 ± 6251	1171*	6012 ± 9385	5138 ± 8376	663*
Pharmacy Costs ($)	8223 ± 8685	6257 ± 6467	1692*	7037 ± 9953	6006 ± 7997	800*
Constipation/IBS-C treatment costs	155 ± 220	67 ± 112	85*	120 ± 245	69 ± 131	51*
Other drug costs	8068 ± 8638	6191 ± 6450	1608*	6917 ± 9913	5937 ± 7986	750*
Total costs ($)	19,813 ± 15,890	13,969 ± 12,697	5108*	19,139 ± 20,211	15,165 ± 16,268	3209*
Prescription treatment sub-group
Total Medical costs ($)	10,013 ± 10,747	7419 ± 8932	2240*	10,974 ± 13,959	8074 ± 10,045	2383*
Typical medical costs	5892 ± 7378	4163 ± 5773	1545*	5626 ± 10,466	3684 ± 6827	1677*
IP costs	1905 ± 5155	866 ± 3082	943*	2380 ± 8259	1092 ± 5161	1066*
OP costs	3237 ± 3581	2669 ± 3237	468*	2723 ± 3473	2252 ± 2973	421*
ED costs	749 ± 1624	628 ± 1949	135	523 ± 1420	340 ± 984	190*
Other medical costs	4121 ± 8187	3255 ± 6339	695	5348 ± 8124	4390 ± 7399	706*
Pharmacy costs ($)	7294 ± 9505	6731 ± 8908	552	7370 ± 24,068	6127 ± 7951	929
Constipation/IBS-C treatment costs	202 ± 366	157 ± 388	43*	154 ± 341	156 ± 295	6
Other drug costs	7091 ± 9388	6573 ± 8815	509	7216 ± 24,050	5971 ± 7895	923
Total costs ($)	17,306 ± 15,690	14,150 ± 14,556	2793*	18,344 ± 29,626	14,201 ± 14,474	3312*

IBS-C, irritable bowel syndrome with constipation; CC, chronic constipation; IP, inpatient; OP, outpatient; ED, emergency department; HCV, home care visits; LTC, long-term care; MHF, mental health facility.

*p Value <0.05.

†Multivariate regression models adjusted for potential confounding factors, including age, gender, ethnicity, CCI, comorbidities with at least 5% prevalence in both groups and a statistically significant difference, and baseline costs.