Table 1. Characteristics of included studies.
| Authors | Year | Study design | DAT | Comparator(s) | Country | Effectiveness |
| Au-Yeung and DiCarlo30 | 2012 | Modelling | Ingestible sensors—record doses ingested via a wearable device | DOT—clinic | USA**** | |
| Bahrainwala et al40 | 2020 | Modelling | Multicomponent intervention—only Digital pillbox§ component extracted | 2 months DOT+4 months SAT and SAT alone | Madagascar* | ✓ |
| Beeler Asay et al34 | 2020 | Observational | VOT—synchronous and asynchronous | DOT—clinic and field | USA**** | |
| Broomhead and Mars38 | 2012 | Observational | Digital pillbox—prompts patient via SMS when doses are missed | DOT—NR | S. Africa*** | |
| Buchman and Cabello46 | 2017 | Observational | VOT—synchronous | DOT—field | USA**** | |
| Daftary et al31 | 2017 | Experimental | Interactive automated voice calls—daily reminders to take medication, reminders for clinic visits, and monthly adherence and side effect assessments | SAT (not costed) | Ethiopia* | |
| Fekadu et al47 | 2021 | Modelling | VOT—synchronous | SAT and DOT (clinic) | USA**** | ✓ |
| Garfein et al41 | 2018 | Observational | VOT—asynchronous with daily SMS or email reminders | DOT—Field+ | USA**** | |
| Gashu et al42—preprint | 2021 | Experimental | SMS reminders—(daily) include graphical messages for illiterate patients | DOT (not costed) | Ethiopia* | |
| Guo et al48 (A) | 2020 | Experimental | VOT—synchronous | DOT—NR | China*** | |
| Guo et al18 (B) | 2020 | Observational | VOT—asynchronous with automated reminders in case of missed recordings | DOT—clinic | China*** | |
| Holzman et al37 | 2018 | Observational | VOT—asynchronous with automated reminders in case of missed recordings | DOT—field | USA**** | |
| Krueger et al23 | 2010 | Observational | VOT—synchronous | DOT—field | USA**** | |
| Lam et al35 | 2019 | Observational | VOT—synchronous and asynchronous | DOT—clinic and field | USA**** | |
| Louwagie et al27 | 2022 | Experimental | SMS reminders—twice weekly (10 TB-related and 7 smoking or alcohol reduction related)+3 motivational counselling sessions | Not explicitly described—likely SAT based on costs included | S. Africa*** | ✓ |
| Manyazewal et al25 | 2022 | Experimental | Digital pillbox—data downloaded at follow-up visits and discussed with patients | DOT—clinic | Ethiopia* | |
| Mukora et al49—abstract | 2022 | Experimental | Digital pillbox—triggers SMS, phone calls and home visits in cases of non-adherence | SAT | S. Africa*** | |
| Nsengiyumva et al19 | 2018 | Modelling | VOT—synchronous, Digital pillbox with SMS reminder in case of missed dose, two-way SMS, phone calls with medication sleeves—branded 99DOTs | SAT and DOT (clinic) | Brazil*** | ✓ |
| Nsengiyumva et al20—preprint | 2023 | Observational | VOT asynchronous, phone calls with medication sleeves—branded 99DOTs | DOT—field (not costed), clinic and family | Tanzania** Moldova*** Philippines** Bangladesh** Haiti** | |
| Peng et al26—abstract | 2014 | Experimental | SMS reminders—no further details are provided in abstract | DOT—NR | China*** | |
| Ravenscroft et al24 | 2020 | Experimental | VOT—asynchronous | DOT—clinic | Moldova*** | |
| Saha et al33 | 2022 | Quasi-experimental | Digital pillbox—reminds patients daily+provides real-time monitoring on app for healthcare workers | NR—but referenced DOT costs from literature | India** | ✓ |
| Salcedo et al32 | 2021 | Modelling | VOT—asynchronous—videos screened first by AI software (branded AiCure) | DOT—combined field (69% of doses) and clinic (31%) | USA**** | ✓ |
| Siddiqui et al36 | 2019 | Observational | VOT—asynchronous | DOT—field | USA**** | |
| Story et al21 | 2019 | Experimental | VOT—asynchronous | DOT—clinic | UK**** | |
| Thompson et al29 | 2022 | Experimental | Phone calls with medication sleeves—branded 99DOTs | DOT—family | Uganda* | ✓ |
| Wade et al22 | 2012 | Observational | VOT—synchronous (with 5% of patients remaining on DOT) | DOT—field | Australia**** | ✓ |
| Waswa et al28—abstract | 2022 | Experimental | Phone calls with medication sleeves—branded 99DOTs | None costed | Uganda* | |
| Yang et al39 | 2022 | Modelling¶ | Digital pillbox—prompts healthcare workers if dose is missed to facilitate follow-up | 2 months DOT—NR+4 months SAT | Morocco**** | ✓ |
Country income level (2021) from World Bank: *low, **lower middle, ***upper middle, ****high.
+Mostly field DOT but a small unspecified number of patients were on clinic DOT in one of the clinics studied.
¶Also contained cost information from retrospective cohort study by Park et al.50
§This study evaluated a multicomponent intervention labelled drone-observed therapy system which included the use of digital pillboxes. Importantly, only the cost of the isolated digital pillbox was extracted which was available from sensitivity analyses.
DOTdirectly observed therapyNRnot reportedSATself-administered therapySMSshort message serviceVOTvideo-observed therapy