Table S2.

Newcastle–Ottawa quality assessment scale

Assessment of quality of a cohort study – Newcastle–
Ottawa Scale
Selection (tick one box in each section)
1. Representativeness of the intervention cohort
a) Truly representative of the average, elderly, community-dwelling resident	□
b) Somewhat representative of the average, elderly, community-dwelling resident	□
c) Selected group of patients, eg, only certain socioeconomic groups/areas	□
d) No description of the derivation of the cohort	□
2. Selection of the nonintervention cohort
a) Drawn from the same community as the intervention cohort	□
b) Drawn from a different source	□
c) No description of the derivation of the nonintervention cohort	□
3. Ascertainment of intervention
a) Secure record (eg, health care record)	□
b) Structured interview	□
c) Written self-report	□
d) Other/no description	□
4. Demonstration that outcome of interest was not present at start of study
a) Yes	□
b) No	□
Comparability (tick one or both boxes, as appropriate)
1. Comparability of cohorts on the basis of the design or analysis
a) Study controls for age, sex, marital status	□
b) Study controls for any additional factors (eg, socioeconomic status, education)	□
Outcome (tick one box in each section)
1. Assessment of outcome
a) Independent blind assessment	□
b) Record linkage	□
c) Self-report	□
d) Other/no description	□
2. Was follow-up long enough for outcomes to occur
a) Yes, if median duration of follow-up ≥6 months	□
b) No, if median duration of follow-up <6 months	□
3. Adequacy of follow-up of cohorts
a) Complete follow-up: all subjects accounted for	□
b) Subjects lost to follow-up unlikely to introduce bias: number lost ≤20%, or description of those lost suggesting no different from those followed	□
c) Follow-up rate <80% (select an adequate %) and no description of those lost	□
d) No statement	□