Background
Methods
Measurement
Comprehensive medication review
Adherence to drug regimen (outcome variable)
Medication-related variables
Medication regimen complexity index (MRCI)
Potentially inappropriate medication (PIM)
Polypharmacy
Medication duplication
Patient-related variables
Demographic characteristics
Smoking status and alcohol use
Memory deficit
Co-morbidity
Knowledge of therapeutic purpose of prescribed medications
Other independent variables
Required co-payment
Number of providers
Statistical analysis
Results
Characteristics of sample
Non-adherence to medications
Knowledge of medications
Bivariate correlates of adherence to drug regimens
Characteristic of Sample | N (%) | Non-Adherence to at least One Medication Regimens N (%) | |||||
---|---|---|---|---|---|---|---|
Dose and interval | Deciding to skip | Forgot to take | Taking Less | Failed to follow food/drink instructions | Failed to follow activity instructions | ||
Gender | |||||||
Male | 141 (35) | 70 (50) |
37 (26)
| 12 (9) | 23 (14) | 101 (72) | 96 (69) |
Female | 259 (65) | 118 (46) |
101 (39)
| 20 (8) | 40 (15) | 189 (73) | 179 (69) |
Age | |||||||
65–74 | 241 (61) | 115 (48) | 88 (37) | 20 (8) | 44 (18) | 201 (83) | 163 (67) |
≥ 75 | 157 (39) | 73 (46) | 50 (32) | 12 (8) | 19 (12) | 139 (89) | 112 (71) |
Education | |||||||
No high school diploma | 99 (25) | 50 (49) | 31 (32) | 7 (7) | 14 (4) | 77 (79) |
76 (78)
|
High school diploma | 301 (75) | 138 (46) | 107 (36) | 25 (8) | 49 16) | 213 (71) |
199 (66)
|
Marital Status | |||||||
Not married | 322 (80) | 146 (46) | 32 (41) | 6 (7) | 11 (14) | 57 (73) | 51 (65) |
Married/living with Partner | 78 (20) | 42 (54) | 106 (33) | 26 (8) | 52 (16) | 233 (73) | 224 (70) |
Co-payment for RX | |||||||
No | 83 (21) |
49 (59)
| 28 (34) | 7 (8) | 10 (12) | 52 (63) |
49 (59)
|
Yes | 317 (79) |
139 (44) | 110 (35) | 25 (8) | 53 (17) | 238 (76) |
226 (72)
|
Number of Providers | |||||||
1–2 | 247 (62) |
96 (39)
|
71 (29)
| 18 (7) | 32 (13) |
161 (66)
|
159 (65)
|
≥ 3 | 153 (38) |
92 (60)
|
71 (46)
| 14 (9) | 31 (20) |
129 (84)
|
116 (76)
|
Number of Pharmacists | |||||||
1 | 287 (72) | 128 (45) | 96 (34) | 19 (7) | 40 (14) | 202 (71) | 188 (66) |
≥ 2 | 113 (28) | 60 (53) | 42 (37) | 13 (12) | 23 (20) | 88 (78) | 87 (77) |
Number of Co-morbidity | |||||||
≤ 3 | 128 (32) |
49 (39)
|
25 (20)
| 7 (6) | 10 (8) | 85 (67) | 76 (60) |
4–7 | 195 (49) |
90 (46)
|
78 (40)
| 17 (9) | 40 (21) | 143 (74) | 141 (73) |
≥ 8 | 77 (19) |
49 (64)
|
35 (45)
| 8 (10) | 13 (17) | 62 (81) | 58 (75) |
Smoking Status | |||||||
Current | 64 (16) | 31 (48) | 22 (34) | 5 (8) | 13 (20) |
36 (56)
| 40 (63) |
Never | 334 (84) | 157 (47) | 116 (35) | 27 (8) | 50 (15) |
254 (76)
| 237 (71) |
Alcohol Use (Drinks/day) | |||||||
No/Occasionally | 355 (89) | 164 (46) | 119 (34) | 27 (8) | 54 (15) | 257 (72) | 246 (69) |
Yes | 43 (11) | 24 (56) | 19 (44) | 5 (12) | 9 (21) | 33 (77) | 29 (67) |
Memory Deficit | |||||||
Not Noticeable | 176 (45) |
69 (39)
| 53 (30) | 11 (6) | 23 (13) | 124 (70) | 130 (74) |
Mild to Moderate | 160 (40) |
79 (49)
| 64 (40) | 15 (9) | 31 (19) | 119 (74) | 102 (64) |
Severe | 61 (15) |
39 (63)
| 21 (34) | 6 (10) | 9 (15) | 46 (75) | 42 (69) |
Medication Knowledge | |||||||
A. How many/often
| |||||||
Correct | 260 (65) |
66 (25)
| 89 (34) | 36 (14) | 24 (9) | 181 (70) | 177 (68) |
Incorrect | 140 (35) |
122 (88)
| 49 (36) | 27 (20) | 8 (6) | 109 (79) | 98 (71) |
B. Purpose of Rx
| |||||||
Correct | 140 (35) |
50 (36)
| 42 (30) | 20 (14) | 13 (9) |
95 (68)
|
83 (59)
|
Incorrect | 258 (65) |
136 (53)
| 96 (37) | 43 (17) | 19 (7) |
195 (76)
|
192 (74)
|
Complexity Index | |||||||
< 10 | 108 (27) |
30 (28)
|
20 (19)
| 7 (6) |
10 (9)
|
84 (78)
|
57 (53)
|
≥ 10 | 290 (73) |
158 (54)
|
118 (41)
| 25 (9) |
53 (18)
|
256 (88)
|
218 (75)
|
Polypharmacy | |||||||
0–4 | 161 (40) |
56 (34)
|
42 (26)
| 25 (15) | 12 (8) |
100 (62)
|
99 (61)
|
≥ 5 | 237 (60) |
134 (57)
|
98 (41)
| 40 (17) | 22 (9) |
190 (80)
|
176 (74)
|
Medication Duplication | |||||||
No | 185 (46) | 81 (44) |
53 (29)
| 13 (7) | 20 (11) | 128 (70) | 119 (65) |
Yes | 215 (54) | 107 (50) |
85 (40)
| 19 (9) | 43 (20) | 162 (77) | 156 (73) |
PIM (AVOID) | |||||||
None | 292 (73) | 132 (46) |
92 (32)
| 24 (8) | 41 (14) |
204 (70)
| 196 (68) |
At Least One | 108 (27) | 56 (52) |
46 (43)
| 8 (7) | 22 (20) |
86 (80)
| 79 (73) |
Multivariate correlates of medication use
Independent variables | Non-Adherence with dosage regimen OR (95% CI) Model 1 | Non-Adherence with dosage regimen OR (95% CI) Model 2 | Taking less - skip or forget OR (95% CI) Model 3 | Taking less - skip or forget OR (95% CI) Model 4 |
---|---|---|---|---|
Gender | ||||
Female | 1 | 1 | 1 | 1 |
Male | 1.16 (0.68–1.98) | 1.21 (0.71–2.07) | 1.59 (0.99–2.55) | 1.53 (0.95–2.46) |
Age | ||||
≥ 75 | 1 | 1 | 1 | 1 |
65–74 | 0.69 (0.41–1.16) | 0.71 (0.43–1.19) | 0.79 (0.51–1.23) | 0.78 (0.50–1.21) |
Education | ||||
No high school diploma | 1 | 1 | 1 | 1 |
High school diploma | 0.72 (0.39–1.32) | 0.73 (0.40–1.41) | 0.85 (0.51–1.43) | 0.92 (0.55–1.54) |
Co-payment for RX | ||||
No |
1
|
1
| 1 | 1 |
Yes |
2.94 (1.59–5.26)
a
|
2.86 (1.54–5.26)
a
| 1.19 (0.69–2.04) | 1.11 (0.65–1.89) |
Memory Deficit | ||||
Not Noticeable |
1
|
1
| 1 | 1 |
Mild to Moderate | 1.27 (0.60–2.63) | 1.27 (0.60–2.70) | 0.87 (0.36–1.32) | 0.68 (0.36–1.32) |
Severe |
2.5 (1.18–5.26)
b
|
2.63 (1.25–5.56)
a
| 0.88 (0.46–1.69) | 0.88 (0.46–1.69) |
Medication Knowledge | ||||
Factor 1 (Dosage/Purpose) |
6.76 (4.24–10.8)
a
|
7.35 (4.53–11.9)
a
| 0.93 (0.74–1.16) | 0.93 (0.73–1.17) |
Factor 2 (Side Effects/Other Instructions) | 1.33 (0.99–1.78) |
1.49 (1.09–2.05)
b
|
1.28 (1.02–1.62)
c
|
1.29 (1.03–1.64)
c
|
Medication Duplication | ||||
No | 1 | 1 | 1 | 1 |
Yes | 1.25 (0.71–2.17) | 0.97 (0.58–1.64) | 1.08 (0.66–1.72) | 0.87 (0.56–1.37) |
PIM | ||||
None | 1 | 1 | 1 | 1 |
At Least One | 1.23 (0.70–2.32) | 1.19 (0.67–2.08) | 0.76 (0.47–1.23) | 0.76 (0.92–1.25) |
Medication Regimen Complexity Index | ||||
< 10 |
1
| NA |
1
| NA |
≥ 10 |
2.02 (1.10–3.90)
c
| - |
2.43 (1.31–4.50)
b
| - |
Polypharmacy | ||||
0–4 | NA | 1 | NA | 1 |
≥ 5 | - | 1.09 (0.60–1.97) | - | 1.66 (0.99–2.80) |
-2 Log Likelihood | 391.2 | 395.5 | 491.9 | 491.6 |
Nagelkerke R-Square | 0.438 | 0.428 | 0.11 | 0.10 |
% of correctly predicted outcome | 77% | 76% | 66% | 66% |