Table 3.
Quality assessment of included studies
| No | Author country, year | Representativeness of patient cases | Selection of the non-exposed cohort | Ascertainment of exposure | Total number of stars (1–3) |
|---|---|---|---|---|---|
| 1 | Katsura [20]. Japan, 1998 | b | c | d | 1 |
| 2 | Tokuyasu [21]. Japan, 2009 | a | c | a | 2 |
| 3 | Takenaka [22]. Japan, 2011 | b | a | a | 3 |
| 4 | Bosch [23]. Spain, 2012 | a | c | a | 2 |
| 5 | Komiya [24]. Japan, 2013 | a | c | d | 1 |
| 6 | Pinargote [25]. Spain, 2015 | a | a | a | 3 |
| 7 | Palacios-Cena [26]. Spain, 2017 | a | c | d | 1 |
| 8 | Nakashima [27]. Japan, 2018 | a | a | a | 3 |
| 9 | Manabe [28]. Japan, 2020 | a | a | a | 3 |
Assessment scores: Representativeness of the exposed cohort: (a) truly representative of the average older persons’ pneumonia in the community, (b) somewhat representative of the average older persons’ pneumonia in the community, (c) selected group, (d) no description of the derivation of the cohort. Selection of the non-exposed cohort: (a) drawn from the same community as the exposed cohort, (b) drawn from a different source, (c) no description of the derivation of the non-exposed cohort. Ascertainment of exposure: (a) secure record, (b) structured interview, (c) written self-report, (d) no description