<span style="font-size: 1em">Study characteristics</span>
A total of 2,811 records were identified through database searching, while an additional 11 were identified through other sources. Extending the search time frame before year 2000 did not result in more suitable publications. After duplicates were removed, 2,426 records were screened, and 2,400 that had titles or abstracts not relevant to the review aim were excluded. Consequently, 26 full-text articles were retrieved and assessed for eligibility. Two records were identified through hand-searching the reference list of full-text articles retrieved. Twenty (20) studies were excluded based on reasons such as studies using summary measures that included family support or implied a certain connection between family members but not support (9), examining the effect of living arrangement (3), assessing the effects of family support on par ticipants aged below 50 years (3), and others (5). Finally, eight studies met all eligibility criteria and were included in the review. Three of the quantitative studies included in the review were from cross sectional surveys, while the remaining five were from longitudinal surveys. Four studies were conducted in Nigeria and two each from Kenya and Ghana. Study participants were mainly recruited from the general population residing in both urban and rural areas. The sample sizes of the studies ranged from 350 to 2,608. Table 37.1 shows characteristics of included studies.