Table 1.
Studies included in the analyses
| Author, Year (references) |
Country | Type of Study |
Total Final Sample |
Length of Follow Up (days) |
Definition of older age |
Adherence Measure |
Definition of Adherence* (%) |
Adherence Young % (n/N) |
Adherence Older % (n/N) |
Internal Validity Grade |
External Validity Grade |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Manfredi, 2000[49] | Italy | Case-control | 105 | 365 | 55 | Pharmacy Refill | 90 | 93 (84) | 90 (21) | Good | Fair |
| Kleeberger, 2001[32] | U.S. | Retrospective cohort | 539 | 4 | 45 | Self Report | 80 | 77 (271) | 78 (268) | Good | Good |
| Pinheiro, 2002[44] | Brazil | Cross sectional | 195 | 2 | 45 | Self Report | 95 | 58 (164) | 52 (31) | Good | Fair |
| Wellons, 2002[45] | U.S. | Retrospective case-control | 269 | 196 | 50 | Chart Review | 100 | 74 (176) | 89 (93) | Fair | Good |
| Johnson, 2003[14] | U.S. | Cross sectional | 2765 | 3 | 50 | Self Report | 90 | 67 (2317) | 74 (441) | Good | Good |
| Tumbarello, 2004[38] | Italy | Case-control | 243 | 183 | 50 | Self Report | 80 | 73 (162) | 84 (81) | Fair | Good |
| Hinkin, 2004[28] | U.S. | Prospective | 148 | 28 | 50 | MEMS | 95 | 26 (109) | 54 (39) | Good | Good |
| Barclay, 2007[16] | U.S. | Prospective | 185 | 28 | 50 | MEMS | 95 | 32 (141) | 77 (44) | Good | Good |
| Silverberg, 2007[29] | U.S. | Retrospective-cohort | 5090 | 365 | 50 | Pharmacy Refill | NR | 85 (4093) | 89 (997) | Fair | Good |
| Sherr, 2010[50] | U.K. | Cross sectional | 479 | 7 | 55 | Self Report | 100 | 37 (333) | 56 (153) | Fair | Good |
| Kyser, 2011[27] | U.S. | Prospective | 528 | 3 | 48 | Self Report | 100 | 83 (399) | 88 (129) | Good | Good |
| Raboud 2011[42] | Canada | Prospective | 779 | 4 | 50 | Self Report | 100 | 83 (447) | 88(332) | Good | Good |
MEMS - Medication Event Monitoring System; NR- not reported
*
Adherence was defined by each study as the percentage of doses taken as prescribed, and each study set specific cutoffs as a definition of adherence.