Table 1.
Summary of included studies on smoking associated with subsequent frailty status change among community-dwelling older people
| Author, year | Location | N | Age* | Female (%) | Smoking definition | Frailty outcome | Follow-up | Finding |
|---|---|---|---|---|---|---|---|---|
| Woods et al., 2005 [18] | USA | 28,181 | 65–79 | 100 % | never, past, current smoking | Incident frailty by modified Fried criteria | 3 years | - Past smoking was associated with incident frailty (OR = 1.12 95 % CI = 1.02–1.23), but not prefrailty (OR = 0.95 95 % CI = 0.89–1.02). |
| - Current smoking was associated with both incidence frailty (OR = 1.76 95 % CI = 1.49–2.09) and prefrailty (OR = 2.90 95 % CI = 2.35–3.57) | ||||||||
| - Unadjusted multinomial logistic regression. | ||||||||
| Ottenbacher et al., 2009 [17] | USA | 777 | 82.5 | 56.4 % | never, past, current smoking | Fried frailty score (range: 0–5) | 10 years | - “Ever smoked” was associated with increase in frailty score at follow-up (beta = 0.36, SE = 0.15, p < 0.05) |
| - Linear regression adjusted for age, gender, education, married, financial strain, diabetes, hip fracture, cancer, stroke, cardiac diseases, arthritis, body mass index and baseline frailty. | ||||||||
| Wang et al., 2013 [23] | China | 3257 | 70.1 | 51.1 % | never, current/past smoking | Frailty index | 15 years | - Current/past smoking was associated with increase in frailty at follow-up (beta = 3.64, SE = 1.62, p = 0.03) in men. |
| - No such association was observed in women. | ||||||||
| - Linear regression adjusted for age, education, baseline frailty index. | ||||||||
| Lee et al., 2014 [24] | China | 3018 | 73.6 | 49.7 % | never, past, current smoking | Change in frailty Category change by Fried criteria | 2 years | - No significant association was observed. |
| - Gender-stratified age-adjusted logistic regression | ||||||||
| Etman et al., 2015 [25] | 11 European countries | 14,082 | >55 | 54.3 % | never, past, current smoking | Worsening in frailty by Fried criteria (robust > prefrail/frail or prefrail > frail) | 2 years | - Current smoking was associated with worsening of frailty status at follow-up (OR = 1.16, 95 % CI = 1.02–1.32, p < 0.05) |
| - Logistic regression adjusted for age, gender, education, baseline frailty and country. |
*Mean age, age range, or age for inclusion
95 % CI: 95 % confidence interval, OR: Odds ratio, SE: Standard error