Prospective memory in non-psychotic first-degree relatives of patients with schizophrenia: a meta-analysis

Figures & data

Figure 1 PRISMA flow.

Table 1 Characteristics of the studies included in the meta-analysis

Studies	Country/area	N	Design, n	Relative		Healthy control		PM measurement	PM type	NOS score
				Age (years)	Education (years)	Age (years)	Education (years)
Wang et al (2010)^Citation25	China	52	Case control 26/26	50.02	11.71	43.38	11.15	Computerized dual task paradigm	Time, Event, Activity, Overall	8
Lui et al (2011)^Citation24	Hong Kong	75	Case control 40/35	23.33	13.13	23.17	13.6	Computerized dual task paradigm	Time, Event, Activity, Overall	7
Zhou et al (2014)^Citation26	China	101	Case control 50/51	28	14	24.3	16.1	C-CAMPROMPT	Time, Event	7
Saleem et al (2018)^Citation27	India	40	Case control 20/20	28.8	14.95	34.4	15.05	Computerized dual task paradigm	Time, Event	6

Abrreviations: C-CAMPROMPT, the Cambridge Prospective Memory Test-Chinese version; NOS, Newcastle-Ottawa Scale; PM, prospective memory.

Table 2 Methodological quality assessment by the Newcastle-Ottawa scale

Studies	Selection				Comparability		Exposure			Total quality score
	The case definition is adequate with independent validation	Represent-ativeness of cases	ommunity controls	Controls with no history of disease	Cases and controls with comparable education	Cases and controls with comparable age	Ascertainment of outcome	Same method of ascertainment for cases and controls	Similar non response rate for both groups
Wang et al (2010)^Citation25	1	1	1	1	1	1	0	1	1	8
Lui et al (2011)^Citation24	1	1	0	1	1	1	0	1	1	7
Zhou et al (2014)^Citation26	1	1	1	1	0	1	0	1	1	7
Saleem et al (2018)^Citation27	1	1	0	1	1	0	0	1	1	6

Table 3 GRADE analyses: prospective memory in non-psychotic first-degree relatives of patients with schizophrenia

Meta-analytic outcomes	Studies (N)	Risk of bias	Inconsistency	Indirectness	Imprecision	Publication bias	Large effect	Overall quality of evidence^a
Overall PM	2 (127)	No	No	No	No	Serious^b	No	+/+/±/;Moderate
Time-based PM	4 (268)	No	No	No	No	Serious^b	No	+/+/±/;Moderate
Event-based PM Activity-based PM	4 (268) 2 (127)	No No	No No	No No	No No	Serious^b Serious^b	No No	+/+/±/;Moderate +/+/±/;Moderate

Notes: ^aGRADE Working Group grades of evidence: High quality=further research is very unlikely to change our confidence in the estimate of effect. Moderate quality=further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality=further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality=we are very uncertain about the estimate. ^bFor continuous outcomes, N<400.

Abbreviations: GRADE, grading of recommendations assessment, development, and evaluation; PM, prospective memory.

Figure 2 Prospective memory in non-psychotic first-degree relatives of patients with schizophrenia: forest plot of overall PM, time-based PM, event-based PM, and activity-based PM.

Abbreviation: PM, prospective memory.

Wang Y, Chan RC, Cui J, et al. Prospective memory in non-psychotic first-degree relatives of patients with schizophrenia. Psychiatry Res. 2010;179(3):285–290. doi:10.1016/j.psychres.2009.07.011

 Web of Science ®Google Scholar

Lui SS, Wang Y, Liu AC, et al. Prospective memory in patients with first-onset schizophrenia and their non-psychotic siblings. Neuropsychologia. 2011;49(8):2217–2224. doi:10.1016/j.neuropsychologia.2011.04.002

 PubMed Web of Science ®Google Scholar

Zhou FC, Hou WM, Wang CY, et al. Prospective memory performance in non-psychotic first-degree relatives of patients with schizophrenia: a controlled study. PLoS One. 2014;9(11):e111562. doi:10.1371/journal.pone.0111562

 PubMed Web of Science ®Google Scholar

Saleem S, Kumar D, Venkatasubramanian G. Prospective memory in first-degree relatives of patients with schizophrenia. Clin Neuropsychol. 2018;32(5):993–1001. doi:10.1080/13854046.2017.1406145

 PubMed Web of Science ®Google Scholar