Table 1.

Severity stage duration and total disease duration estimates and Q-statistic

	Articles (n)	Estimates (n)	Stage duration (weighted average, y)	Q-statistic
Severity Stage Duration	15	42
Severity stage onset to conversion	8	21
MCI/very mild dementia	8	11	3.11	2.29
Mild	2	4	3.32	0.39
Moderate	2	4	1.99	0.42
Severe	1	2	1.30	0.64
Overall disease onset to study entry	5	15
MCI/very mild dementia	5	5	2.27	0.25
Mild	4	4	2.96	0.89
Moderate	4	4	4.90	0.83
Severe	2	2	8.94	1.19
Diagnosis to death	1	2
MCI/very mild or mild dementia	1	1	7.17	–
Moderate to severe	1	1	6.58	–
Overall disease onset to death	1	4
MCI/very mild dementia	1	1	12.5	–
Mild	1	1	11.6	–
Moderate	1	1	11.8	–
Severe	1	1	6.7	–
Disease Duration	93	144
Overall disease onset to diagnosis	5	6	2.63	1.32
Overall disease onset to study entry	58	78	3.03	2.19
Diagnosis to death	14	38	5.12	1.53
Overall disease onset to death	14	20	6.61	3.69
Study Entry to death	2	2	6.77	0.06