Measurement and reporting of adherence to OACs by included studies
| Study (year) | Adherence measure (threshold) | Adherence results over 6 months | Adherence results over 1 year | ||
| Mean adherence score ± SD | Proportion adherent | Mean adherence score ± SD | Proportion adherent | ||
| Proportion days covered (PDC) | |||||
| Alberts et al (2016)35 | PDC (>80%) | NA | NA | NA | Overall: 0.70 A and D: 0.68 R: 0.73 |
| Borne et al (2017)37 | PDC (>80%) | NA | NA | Overall: 0.85±0.19 A: 0.89±0.14 D: 0.84±0.20 R: 0.86±0.18 | Overall: 0.72 A: 0.77 D: 0.71 R: 0.75 |
| Brown et al (2016)64 | PDC (≥80%) | A: 0.75±0.29 D: 0.67±0.33 R: 0.75±0.31 | A: 0.62 D: 0.54 R: 0.64 | NA | NA |
| Casciano et al (2013)38 | PDC (>80%) | NA | NA | NA | W: 0.41 |
| Coleman et al (2016)40 | PDC (>80%) | D: 0.77±0.32 R: 0.82±0.30 | D: 0.65 R: 0.74 | D: 0.65±0.37 R: 0.73±0.35 | D: 0.52 R: 0.62 |
| Coleman et al (2017)39 | PDC (≥80%) | NA | A: 0.57 and 0.62 R: 0.54 and 0.58 (Two different databases were used for this study hence two adherence results per drug.) | NA | NA |
| Crivera et al (2015)41 | PDC (>80%) | NA | NA | Index DOAC: A: 0.83±0.20 D: 0.81±0.22 R: 0.86±0.19 Any OAC: A: 0.84±0.18; D: 0.85±0.18; R: 0.87±0.17; | Index DOAC: A: 0.71 D: 0.68 R: 0.75 Any OAC: A: 0.71 D: 0.73 R: 0.77 |
| Deshpande et al (2018)43 | PDC (≥80%) | NA | R and D: 0.65 | NA | R and D: 0.54 |
| Deshpande et al (2018)42 | PDC (≥80%) | R and D: 0.86±SD missing | R and D: 0.77 | R and D: 0.85±SD missing | R and D: 0.76 |
| Forsuland et al (2016)45 | PDC (>80%) | NA | NA | NA | A: 0.93 D: 0.92 R: 0.96 |
| Gorst-Rasmussen et al (2015)47 | PDC (>80%) | 0.84±0.28 | NA | NA | D: 0.77 |
| Harper et al (2018)48 | PDC (>80%) | NA | NA | NA | D: 0.84 |
| Manzoor et al (2017)50 | PDC high (≥90%) | Overall: 0.78±28.40 A: 80.90±24.9 D: 78.60±27.70 R: 76.50±30.70 | PDC90 0.55 | Overall: 72.80±32.20 A: No users of A at 12 months D: 73.4±31.6; R: 69.7±34.8 | PDC90 0.34 |
| Maura et al (2017)52 | PDC>80 | NA | NA | NA | Index OAC: Overall: 0.71 D: 0.70 R: 0.72 |
| McHorney et al (2017)55 | PDC (>80% and >90%) | NA | PDC 80: A: 0.76 D: 0.69 R: 0.80 W: 0.65 PDC90: A: 0.57 D: 0.51 R: 0.64 W: 0.47 | NA | NA |
| McHorney et al (2018)56 | PDC (>80% and NR2>90%) | NA | PDC80: A:0.78 R: 0.82 PDC90: A: 0.60 R: 0.67 | NA | NA |
| Pham et al (2019)58 | PDC (>80%) | Index OAC: A: 0.76±0.29 D: 0.67±0.33 R: 0.72±0.32 | Index OAC: A: 0.63 D: 0.53 R: 0.58 | Index OAC: A: 0.70±0.33 D: 0.57±0.36 R: 0.64±0.36 Any OAC: A: 0.73±0.31 D: 0.64±0.34 R: 0.68±0.34 | Index OAC: A: 0.56. D: 0.41 R: 0.50 |
| Shore et al (2014)59 | PDC (>80%) | NA | D: 0.28 | NA | NA |
| Sørensen et al(2017)60 | PDC (>80%) | NA | Odds of being adherent R: reference; A: 0.79 (0.69–0.92) D: 0.72 (0.66–0.80) VKA: 0.76 (0.69–0.83) | NA | NA |
| Tsai et al (2013)61 | PDC (no threshold) | D: warfarin-naïve: 0.67±0.36 warfarin-experienced: 0.71±0.35 | NA | NA | NA |
| Yao et al (2016)62 | PDC (>80%) | NA | Overall: 47.5% A: 0.52 D: 0.46 R: 0.48 W: 0.39 | NA | NA |
| Medication possession ratio (MPR) | |||||
| Beyer-Westendorf et al (2016)36 | MPR (>0.8) | D: 0.67±SD missing R: 0.76±SD missing | D: 0.50 R: 0.61 | D: 0.64±SD missing R: 0.75±SD missing | D: 0.48 R: 0.63 |
| Eapen et al (2014)44 | MPR (no threshold) | NA | NA | Median (IQR): 0.77 (0.51–0.98) | NA |
| Gomez-lumberas et al (2018)46 | MPR (>0.8) | NA | NA | NA | A: 0.62 |
| Jacobs et al (2018)49 | MPR (≥0.8) | NA | NA | NA | Sweden: 0.95 Netherlands: 0.93 |
| McHorney et al(2017)55 | MPR (>0.8) | NA | NA | A: 0.85±0.2 D: 0.81±0.2 R: 0.86±0.2 W: 0.80±0.2 | A: 0.76 D: 0.66 R: 0.78 W: 0.59 |
| Zhou et al (2015)63 | MPR (>0.8) | D: 0.73±0.30 | D: 0.59 | D: 0.65±0.35 | D: 0.51 |
| Mueller et al (2017)57 | MPR >80* | NA | NA | NA | DOACs: 0.82 A: 0.88 D: 0.65 R: 0.83 |
| Márquez-Contrera et al (2016)51 | CP >80% | NA | R: Global compliance: 0.84 Daily compliance: 0.84 % therapeutic cover: 90.04% | NA | R: Global compliance: 0.80 Daily compliance: 0.80 % therapeutic cover: 89.25% |
| McAlister et al (2018)53 | TTR >65% (INR2–3) | NA | W: Per cent patients with time in therapeutic range: 4.11% | NA | NA |
Drug specific proportion of adherent patients was calculated as the per cent of total number of patients taking the respective drug in the study and not the total number of patients in the study.
*Referred to as medication refill adherence in the study (total days' supply/total days in study) x 100.
aHR, adjusted HR; CP, compliance percentage; DOAC, direct oral anticoagulant; MPR, medication possession ratio; NA, not available/not applicable; OAC, oral anticoagulant; PDC, proportions days covered; TTR, time in therapeutic range; VKA, vitamin K antagonist.