Table 1.
Characteristics of included studies
| Category | Subcategory | Studies, n (%) | |
| Publication year | 2016 | 22 (20) | |
| 2017 | 17 (15) | ||
| 2018 | 23 (21) | ||
| 2019 | 22 (20) | ||
| 2020 | 18 (16) | ||
| 2021 | 9 (8) | ||
| Analysis method | Quantitative | 74 (67) | |
| Qualitative | 21 (19) | ||
| Mixed methods | 14 (13) | ||
| Narrative synthesis | 2 (2) | ||
| Study location | Asia | India | 42 (38) |
| Bangladesh | 9 (8) | ||
| Nepal | 4 (4) | ||
| Pakistan | 3 (3) | ||
| Myanmar | 2 (2) | ||
| Iran | 2 (2) | ||
| Sri Lanka | 1 (1) | ||
| South America | Brazil | 7 (6) | |
| Peru | 2 (2) | ||
| Africa | Kenya | 14 (13) | |
| Ethiopia | 7 (6) | ||
| Malawi | 4 (4) | ||
| Uganda | 3 (3) | ||
| South Africa | 2 (2) | ||
| Sierra Leone | 1 (1) | ||
| Nigeria | 1 (1) | ||
| Egypt | 1 (1) | ||
| Zambia | 1 (1) | ||
| Namibia | 1 (1) | ||
| Ghana | 1 (1) | ||
| North America | Haiti | 1 (1) | |
| Multiple nations | 1 (1) | ||
| Healthcare services in slums* | Healthcare accessing | 32 | |
| Healthcare service utilisation | 73 | ||
| Provision of healthcare services | 10 | ||
| Total | 111 (100) | ||
*One study reported factors related to both healthcare accessing and healthcare utilisation and three studies reported factors related to both healthcare utilisation and provision of healthcare services.