Summary of knowledge gaps
| Area | Missing information | Impact |
| Global burden of different types of nonadherence | A better determination of the distribution of nonadherence between late/noninitiation, suboptimal implementation and discontinuation. | Stratification of settings/populations on the basis of the interventions that might be useful, including changes to healthcare processes and systems. |
| Whether there are substantial differences between (and within) countries. Who displays each pattern. | Intelligent intervention design. | |
| Why different patterns are displayed. | ||
| Trials versus normal treatment pathway | The extent to which nonadherence varies between clinical trials and in normal care settings. | Aids decision-making surrounding the adoption of new regimens (operational efficacy). |
| Suboptimal implementation patterns | Improved estimates of the frequency and types of suboptimal implementation, explicitly excluding doses missed due to discontinuation. | Stratification of settings (e.g. by healthcare system)/populations (e.g. by patient characteristics) on the basis of the interventions that might be useful. |
| Variability in patterns between settings and patients. | Intelligent intervention design. | |
| Causes of these patterns. | ||
| Relationship between the different components of adherence | Whether early-stage indicators of nonadherence can predict later issues with nonadherence. | Inform clinicians as to which nonadherence patterns should trigger active intervention. |
| Relationship between patterns and patient outcomes | Specific mapping of how different nonadherence types and patterns impact treatment failure (and the need to restart treatment) and the development of drug resistance, in order to prioritise cost-effective intervention development and roll-out. | Stratification of settings/populations on the basis of the interventions that might be useful and when they should be “stepped up”. |
| Intelligent intervention design. | ||
| Inform clinicians as to which nonadherence patterns should trigger active intervention. | ||
| Regimen forgiveness | The impact of the commonly displayed adherence patterns on forgiveness. | Inform regimen design. |
| The implications of nonadherence to each drug within the multidrug regimen. |