Table A1.

NOS checklist.

(1) Representativeness of the exposed cohort

(★)-moderate-to-severe tinnitus

(★)-tinnitus patients

(☆)-selection of individuals

(☆)-no description

(2) Selection of the non-exposed cohort

(★)-same as exposed cohort

(☆)-other source

(☆)-no description

(3) Ascertainment of exposure

(★)-objective measure

(☆)-questionnaire

(☆)-no description

(4) Demonstration that outcome of interest was not present at start of study

(★)-pre-stimulation tinnitus outcome available

(☆)-pre-stimulation tinnitus outcome not available

(1) Comparability of cohorts on the basis of the design or analysis

(★)-inclusion based on tinnitus severity

(☆)-no inclusion based on tinnitus severity

(★)-inclusion based on HL

(☆)-no inclusion based on HL

(1) Assessment of outcome

(★)-questionnaire

(☆)-self report

(☆)-no description

(☆)-other

(2) Was follow-up long enough for outcomes to occur

(★)-at least during stimulation

(☆)-no data

(3) Adequacy of follow up of cohorts

(★)-no missing data

(★)-<10% missing data

(☆)->10% missing data

(☆)-no description

★ 1 point; ☆ 0 point.