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. Author manuscript; available in PMC: 2012 Dec 26.
Published in final edited form as: Arch Gen Psychiatry. 2006 May;63(5):530–538. doi: 10.1001/archpsyc.63.5.530

Table 2.

Assessment of Study Quality

Quality Indicators From Newcastle-Ottawa Scale40*
Studies 1 2 3 4 5A 5B 6 7 8
Case-control
  French et al,10 1985 No Yes No Yes Yes Yes Yes Yes No
  Agbayewa,11 1986 No Yes No No Yes Yes No Yes No
  Shalat et al,13 1987 Yes No Yes Yes Yes Yes No Yes No
  Broe et al,12 1990 Yes Yes No Yes Yes Yes Yes Yes No
  Kokmen et al,6 1991 No Yes No Yes Yes Yes No Yes No
  Speck et al,7 1995 No Yes Yes Yes Yes Yes Yes Yes No
  Tsolaki et al,8 1997 Yes No Yes Yes No No No No No
  Zalsman et al,14 2000 No Yes No No No No No No No
  Green et al,9 2003 Yes Yes Yes Yes Yes Yes No No No
Cohort
  Buntinx et al,15 1996 Yes Yes Yes Yes Yes Yes Yes Yes Yes
  Devanand et al,16 1996 Yes Yes Yes Yes Yes Yes Yes No Yes
  Chen et al,20 1997 Yes Yes Yes Yes Yes Yes Yes Yes Yes
  Palsson et al,21 1999 Yes Yes Yes Yes Yes Yes No Yes Yes
  Li et al,22 2001 No No No Yes No No No No Yes
  Lindsay et al,23 2002 Yes Yes No Yes Yes Yes Yes Yes Yes
  Zubenko et al,17 2003 Yes Yes Yes Yes No No Yes No Yes
  Kessing and Nilsson,18 2003 Yes Yes Yes Yes No No Yes Yes Yes
  Steffens et al,24 2004 Yes Yes Yes Yes Yes Yes No Yes Yes
  Dal Forno etal,19 2005 No Yes No Yes Yes Yes No Yes No
  Andersen et al,25 2005 Yes Yes No Yes Yes Yes No Yes Yes
*

For case-control studies, 1 indicates cases independently validated; 2, cases are representative of population; 3, community controls; 4, controls have no history of Alzheimer disease; 5A, study controls forage; 5B, study controls for additional factor(s); 6, ascertainment of exposure by blinded interview or record; 7, same method of ascertainment used for cases and controls; and 8, nonresponse rate the same for cases and controls. For cohort studies, 1 indicates exposed cohort truly representative; 2, nonexposed cohort drawn from the same community; 3, ascertainment of exposure; 4, outcome of interest not present at start; 5A, cohorts comparable on basis of age; 5B, cohorts comparable on other factor(s); 6, quality of outcome assessment; 7, follow-up long enough for outcomes to occur; and 8, complete accounting for cohorts.