Real-World Patterns of Basal Insulin Use with Other Diabetes Medications Among People with Type 2 Diabetes Between 2014 and 2020
- Open Access
- 15.05.2023
- Original Research
Abstract
Why carry out this study? |
Basal insulin is an important component of the type 2 diabetes (T2D) treatment armamentarium. However, treatment guidelines for T2D have evolved from a glucose-centric approach to a more targeted approach and, consequently, basal insulin is positioned below novel therapies such as glucagon-like peptide 1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT-2is). |
GLP-1RAs and SGLT-2is, which have demonstrated cardiovascular and renal benefits, are recommended and preferred over basal insulin for people with T2D who have established or are at high risk of atherosclerotic cardiovascular disease and/or renal disease. |
Against the backdrop of changing treatment guidelines for T2D, this study aimed to describe real-world medication usage patterns among those with T2D who initiate and use basal insulin. |
What was learned from this study? |
Real-world initiation of basal insulin remained stable between 2014 and 2020 despite an increase in the use of newer non-insulin medications, such as GLP-1RAs and SGLT-2is, during this period. |
A significant proportion of people who had initiated basal insulin therapy intensified treatment using bolus insulin early within the first year of basal insulin use. |
GLP-1RAs and SGLT-2is were added earlier on in the treatment regimen among those who had initiated basal insulin therapy. However, among those who initiated therapy with the basal insulin-GLP-1RA combination, the proportion of PwT2D with a history of underlying cardiovascular disease was not higher among GLP-1RA first users. |
It is likely that clinical practice and professional society guidelines that recommend GLP-1RAs and SGLT-2is over basal insulin for cardiorenal protection are not the sole drivers of their increasing use in PwT2D who initiate basal insulin therapy. |
Introduction
Insulin’s Place in the Treatment Algorithm for Type 2 Diabetes
Evolution of T2D Clinical and Professional Society Treatment Guidelines Over Time
Objectives
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To describe and compare demographic and clinical characteristics in the year prior to basal insulin initiation (index date) between cohorts, and
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To describe and compare diabetes medication utilization patterns in the year prior to and the year after initiation of basal therapy between cohorts.
Methods
Data Source and Study Design
Study Population
Study Variables
Statistical Analysis
Results
Characteristics of Basal Insulin Initiators Among PwT2D
Demographic Characteristics
Variable | Cohort 1 (2015) (N = 17,801 PwT2D) | Cohort 2 (2017) (N = 13,487 PwT2D) | Cohort 3 (2019) (N = 10,870 PwT2D) |
|---|---|---|---|
Total number of PwT2D in cohort year | 948,805 | 834,320 | 622,455 |
New basal insulin initiators, n (%) | 17,801 (1.9) | 13,487 (1.6) | 10,870 (1.8) |
Age at index date, years | |||
Mean [SD] | 55.9 [11.7] | 54.0 [10.7]a,b | 52.1 [9.6]c |
Sex, n (%) | |||
Female | 8403 (47.2) | 6285 (46.6) | 5132 (47.2) |
Primary payer at index date, n (%) | |||
Commercial | 12,212 (68.6) | 9506 (70.5)a,b | 7905 (72.7)c |
Medicaid | 2389 (13.4) | 2606 (19.3) | 2637 (24.3) |
Medicare | 3200 (18.0) | 1375 (10.2) | 328 (3.0) |
Macrovascular conditions, n (%) | |||
Cerebrovascular disease | 1232 (6.9) | 830 (6.2)a | 606 (5.6)c |
Congestive heart failure | 1130 (6.3) | 827 (6.1) | 648 (6.0) |
Coronary arterial disease | 2298 (12.9) | 1560 (11.6)a,b | 1062 (9.8)c |
Myocardial infarction | 560 (3.1) | 475 (3.5) | 381 (3.5) |
Peripheral arterial disease | 791 (4.4) | 347 (2.6)a | 287 (2.6)c |
Unstable angina | 356 (2.0) | 121 (0.9)a | 99 (0.9)c |
Microvascular conditions, n (%) | |||
End-stage renal disease | 199 (1.1) | 77 (0.6)a | 60 (0.6)c |
Chronic kidney disease stages 3–4 | 1043 (5.9) | 671 (5.0)a,b | 459 (4.2)c |
Peripheral neuropathy | 3231 (18.2) | 2546 (18.9) | 2108 (19.4)c |
Retinopathy | 431 (2.4) | 988 (7.3)a | 830 (7.6)c |
Other conditions, n (%) | |||
Hyperlipidemia | 11,326 (63.6) | 9173 (68.0)a | 7280 (67.0)c |
Hypertension | 13,300 (74.7) | 9937 (73.7)a | 7935 (73.0)c |
Severe liver disease | 165 (0.9) | 167 (1.2)a,b | 178 (1.6)c |
Obesity | 3867 (21.7) | 3765 (27.9)a,b | 3373 (31.0)c |
Adapted Diabetes Complications Severity Index | |||
Mean [SD] | 1.1 [1.6] | 1.0 [1.4]a | 1.0 [1.4]c |
Charlson Comorbidity Index | |||
Mean [SD] | 2.3 [2.0] | 2.5 [2.1]a | 2.5 [2.1]c |
Diabetes with complications, n (%) | 6778 (38.1) | 5277 (39.1) | 4179 (38.4) |
Clinical Characteristics
Medication Use Patterns of Basal Insulin Initiators Among PwT2D
Pre-index diabetic medications, n (%)d,e | Cohort 1 (2015) (N = 17,801 PwT2D) | Cohort 2 (2017) (N = 13,487 PwT2D) | Cohort 3 (2019) (N = 10,870 PwT2D) |
|---|---|---|---|
Metformin | 12,443 (69.9) | 9843 (73.0)a,b | 7600 (69.9) |
Thiazolidinedione | 1543 (8.7) | 1163 (8.6) | 938 (8.6) |
Sulfonylurea | 8760 (49.2) | 6466 (47.9)a,b | 4453 (41.0) |
Meglitinide | 307 (1.7) | 191 (1.4)a,b | 101 (0.9)c |
Dipeptidyl peptidase-4 inhibitor | 5302 (29.8) | 4025 (29.8)b | 2701 (24.8)c |
Sodium-glucose cotransporter-2 inhibitor | 2034 (11.4) | 2481 (18.4)a,b | 2233 (20.5)c |
Glucagon-like peptide-1 receptor agonist | 2629 (14.8) | 2722 (20.2)a,b | 2743 (25.2)c |
Post-index diabetic medications, n (%)e | Cohort 1 (N = 17,801 PwT2D) | Cohort 2 (N = 13,487 PwT2D) | Cohort 3 (N = 10,870 PwT2D) |
|---|---|---|---|
Metformin | 12,776 (71.8) | 10,137 (75.2)a | 8132 (74.8)c |
Thiazolidinedione | 1282 (7.2) | 956 (7.1) | 789 (7.3) |
Sulfonylurea | 7321 (41.1) | 234 (38.8)a,b | 3656 (33.6)c |
Meglitinide | 276 (1.6) | 169 (1.3)a,b | 95 (0.9)c |
Dipeptidyl peptidase-4 inhibitor | 4694 (26.4) | 3380 (25.1)a,b | 2187 (20.1)c |
Sodium-glucose cotransporter-2 inhibitor | 2384 (13.4) | 2492 (18.5)a,b | 2533 (23.3)c |
Glucagon-like peptide-1 receptor agonist | 2971 (16.7) | 3031 (22.5)a,b | 3311 (30.5)c |
Bolus insulin | 2785 (15.6) | 1891 (14.0)a | 1524 (14.0)c |
Basal insulin | 17,801 (100.0) | 13,117 (97.3)a,b | 10,403 (95.7)c |
Mixed insulin | 308 (1.7) | 172 (1.3)a | 120 (1.1)c |
Glucagon-like peptide-1 receptor agonist and basal insulin combination | 0 (0.0) | 639 (4.7)a,b | 665 (6.1)c |
Analysis of Time to First Fill of Second Drug Class Among Basal Insulin Initiators
Time from index date to first fill of second drug class (days) | Cohort 1 (2015) (N = 13,831 PwT2D) | Cohort 2 (2017) (N = 9263 PwT2D) | Cohort 3 (2019) (N = 7000 PwT2D) |
|---|---|---|---|
GLP-1RA added | |||
n (%) | 920 (6.7) | 841 (9.1) | 968 (13.8) |
Mean [SD] | 132.4 [114.3] | 135.0 [111.9]a | 120.5 [109.6]b |
SGLT-2i added | |||
n (%) | 806 (5.8) | 548 (5.9) | 598 (8.5) |
Mean [SD] | 131.5 [111.4] | 119.2 [109.7]c | 113.3 [111.0]b |
Bolus insulin added | |||
n (%) | 1952 (14.1) | 1215 (13.1) | 915 (13.1) |
Mean [SD] | 113.4 [106.4] | 105.9 [106.9]a | 93.8 [104.6]b |
Mixed insulin added | |||
n (%) | 189 (1.4) | 100 (1.1) | 61 (0.9) |
Mean [SD] | 140.2 [107.3] | 131.3 [102.8] | 139.5 [115.9] |
Characteristics of Basal Insulin First Initiators, GLP-1RA First Initiators, and Concomitant Initiators
Variable | Cohort 1 (2015) (N = 3561 PwT2D; 20.0%) | Cohort 2 (2017) (N = 3933 PwT2D; 29.2%) | Cohort 3 (2019) (N = 4105 PwT2D; 37.8%) | ||||||
|---|---|---|---|---|---|---|---|---|---|
Concomitant initiators (n = 402; 11.3%) | Basal insulin–first initiators (n = 1033, 29.0%) | GLP-1RA-first initiators (n = 2126; 59.7%) | Concomitant initiators (n = 600; 15.3%) | Basal insulin–first initiators (n = 1069; 27.2%) | GLP-1RA-first initiators (n = 2264; 57.6%) | Concomitant initiators (n = 782; 19.0%) | Basal insulin–first initiators (n = 1068; 26.0) | GLP-1RA-first initiators (n = 2255; 54.9%) | |
Age at index date, years | |||||||||
Mean [SD] | 53.3 [10.4] | 52.3 [10.0] | 55.2 [9.9]a,b | 51.9 [10.2] | 52.2 [9.7] | 54.0 [9.1]a,b | 50.7 [9.3] | 50.7 [9.4] | 52.6 [8.6]a,b |
Sex, n (%) | |||||||||
Female | 218 (54.2) | 542 (52.5) | 1109 (52.2) | 294 (49.0) | 548 (51.3) | 1158 (51.1) | 379 (48.5)c | 568 (53.2) | 1169 (51.8) |
Primary payer at index date, n (%) | Cohort 1b | Cohort 2b,c | Cohort 3b,c | ||||||
Commercial | 307 (76.4) | 827 (80.1) | 1637 (77.0) | 489 (81.5) | 817 (76.4) | 1785 (78.8) | 629 (80.4) | 803 (75.2) | 1787 (79.2) |
Medicaid | 47 (11.7) | 121 (11.7) | 186 (8.7) | 67 (11.2) | 182 (17.0) | 303 (13.4) | 139 (17.8) | 238 (22.3) | 405 (18.0) |
Medicare | 48 (11.9) | 85 (8.2) | 303 (14.3) | 44 (7.3) | 70 (6.5) | 176 (7.8) | 14 (1.8) | 27 (2.5) | 63 (2.8) |
Macrovascular conditions, n (%) | |||||||||
Cerebrovascular disease | 29 (7.2)c | 47 (4.5) | 106 (5.0) | 33 (5.5) | 47 (4.4) | 89 (3.9) | 27 (3.5) | 48 (4.5) | 86 (3.8) |
Congestive heart failure | 16 (4.0) | 48 (4.6) | 65 (3.1)b | 29 (4.8) | 43 (4.0) | 89 (3.9) | 34 (4.3) | 46 (4.3) | 80 (3.5) |
Coronary arterial disease | 52 (12.9) | 107 (10.4) | 235 (11.1) | 51 (8.5) | 120 (11.2) | 208 (9.2) | 49 (6.3)c | 94 (8.8) | 224 (9.9)a |
Myocardial infarction | 13 (3.2) | 21 (2.0) | 33 (1.6)a | 15 (2.5) | 39 (3.6) | 42 (1.9)b | 16 (2.0) | 37 (3.5) | 54 (2.4) |
Peripheral arterial disease | 12 (3.0) | 31 (3.0) | 87 (4.1) | 12 (2.0) | 29 (2.7) | 51 (2.3) | 17 (2.2) | 16 (1.5) | 63 (2.8)b |
Unstable angina | 11 (2.7) | 14 (1.4) | 33 (1.6) | 6 (1.0) | 12 (1.1) | 14 (0.6) | 11 (1.4) | 8 (0.7) | 13 (0.6)a |
Microvascular conditions, n (%) | |||||||||
End-stage renal disease | 1 (0.2) | 4 (0.4) | 6 (0.3) | 1 (0.2) | 4 (0.4) | 3 (0.1) | 0 (0.0)c | 6 (0.6) | 5 (0.2) |
CKD stages 3–4 | 10 (2.5) | 41 (4.0) | 125 (5.9)a,b | 16 (2.7) | 38 (3.6) | 104 (4.6)a | 16 (2.0)c | 46 (4.3) | 91 (4.0)a |
Peripheral neuropathy | 78 (19.4) | 193 (18.7) | 429 (20.2) | 101 (16.8) | 208 (19.5) | 489 (21.6)a | 135 (17.3) | 215 (20.1) | 513 (22.7)a |
Retinopathy | 7 (1.7) | 20 (1.9) | 51 (2.4) | 37 (6.2) | 73 (6.8) | 193 (8.5) | 55 (7.0) | 86 (8.1) | 200 (8.9) |
Other conditions, n (%) | |||||||||
Hyperlipidemia | 257 (63.9) | 682 (66.0) | 1580 (74.3)a,b | 411 (68.5) | 717 (67.1) | 1810 (79.9)a,b | 530 (67.8) | 711 (66.6) | 1796 (79.6)a,b |
Hypertension | 303 (75.4) | 775 (75.0) | 1678 (78.9)b | 434 (72.3) | 784 (73.3) | 1811 (80.0)a,b | 563 (72.0) | 764 (71.5) | 1769 (78.4)a,b |
Severe liver disease | 5 (1.2) | 10 (1.0) | 16 (0.8) | 2 (0.3) | 8 (0.7) | 16 (0.7) | 9 (1.2) | 11 (1.0) | 31 (1.4) |
Obesity | 105 (26.1) | 290 (28.1) | 590 (27.8) | 196 (32.7) | 352 (32.9) | 763 (33.7) | 265 (33.9) | 364 (34.1) | 832 (36.9) |
Adapted Diabetes Complications Severity Index (mean [SD]) | 0.9 [1.3] | 0.9 [1.4] | 1.0 [1.4]b | 0.8 [1.2] | 0.8 [1.4] | 0.8 [1.2] | 0.8 [1.3] | 0.9 [1.3] | 0.9 [1.3] |
Charlson Comorbidity Index (mean [SD]) | 2.0 [1.6] | 2.0 [1.6] | 2.3 [1.8]a,b | 2.2 [1.7] | 2.3 [1.8] | 2.5 [1.9]a,b | 2.3 [1.9] | 2.4 [2.0] | 2.6 [2.0]a,b |
HbA1c (%) pre-index, most recent (mean [SD]) | 9.7 [2.0] | 9.7 [1.9] | 9.3 [1.7] | 10.3 [2.2] | 10.4 [1.9] | 9.3 [1.6]a,b | 10.2 [2.1] | 10.5 [2.2] | 9.3 [1.7]a,b |
People with HbA1c available during pre-index, n (%) | 28 (7.0) | 62 (6.0) | 127 (6.0) | 29 (4.8) | 51 (4.8) | 126 (5.6) | 80 (10.2)c | 69 (6.5) | 213 (9.4)b |
HbA1c (%), post-index, most recent (mean [SD]) | 8.4 [1.8] | 8.3 [1.9] | 8.6 [1.7] | 8.1 [1.9] | 8.1 [1.7] | 8.3 [1.7] | 8.1 [1.9] | 8.7 [2.4] | 8.4 [1.9] |
People with HbA1c available during post-index, n (%) | 26 (6.5) | 69 (6.7) | 106 (5.0) | 36 (6.0) | 69 (6.5) | 123 (5.4) | 69 (8.8) | 82 (7.7) | 205 (9.1) |
Diabetes with complications, n (%) | 150 (37.3) | 347 (33.6) | 797 (37.5)b | 208 (34.7) | 399 (37.3) | 883 (39.0) | 255 (32.6)c | 416 (39.0) | 923 (40.9)c |