Table 1.

Methodological flaws in controlled observational studies of tube feeding elderly patients

Study (year)	Tube survival benefita	Selection bias	Poor or unmatched control group	No group comparison table	Poor inclusion criteria – mild dysphagia	Poor exclusion criteria—too sick (%inpatient)	Cohort not defined by cognitive impairment	Mixed diagnosis in tube group (% dementia)	Equates cognitive impairment and dementia	Mixed tube type	Imprecise measure—database study	Poor outcome measure—tube prior to baseline	Sample size < 100
Mitchell, Kiely, and Lipsitz (1998)	Harm	+	++		+	+	+	+ (31%)	+	+	+	+++
Nair, Hertan, and Pitchumoni (2000)	Harm	+	++	+	?	+ (100%)							+
Alvarez-Fernández et al. (2005)	Harm	+	++	+/−	+++							+	+
Arinzon, Peisakh, and Berner (2008)	Harm	+	+++		?	?		…b	+	+		+?
Cintra et al. (2014)	Harm	+	+++		…c	+ (84%)				+			+
Mitchell, Kiely, and Lipsitz (1997)	0	+	+		+	+		+ (53%)	+	+	+	?
Meier et al. (2001)	0	+	+	…d	?	+ (100%)							+
Murphy and Lipman (2003)	0	+	???	+	?	?		…b					+
Teno et al. (2012)	0	+	++		++	+					+
Cowen, Simpson, and Vettese (1997)	Benefit	+	+++	+	…c	+ (100%)	+	+ (20%)
Rudberg et al. (2000)	Benefit	+	+		…e	+	…f	+	+	+	+
Jaul, Singer, and Calderon-Margalit (2006)	Benefit	+	+++		?	?	+	+ (68%)				?	+
Shintani (2013)	Benefit	+	+		…g	?	+	+ (8–16%)				?+	+
Peck, Cohen, and Mulvihill (1990)	?	+	+++		?	?	+		+	+		++

Note: “+” indicates that this flaw affects study design; “?” indicates that insufficient information was reported to determine if this flaw affects study design.

^a“Benefit” means tube feeding demonstrated survival benefit. “0” means there was no significant benefit. “Harm“ means tube feeding demonstrated increased mortality. “?” means survival data was not reported.

^bLimited to dementia, but vague criteria for diagnosis of dementia.

^cExcluded mild dysphagia with formal swallowing evaluation.

^dNo direct comparison table, but reports a few selected risk factors for tube placement.

^eUsed database variables to select more severe swallowing problems, but no formal swallowing evaluation.

^fSelected patients on basis of swallowing problems, but results were similar analyzing subgroup with severe cognitive impairment.

^gIncluded mild dysphagia, but reported levels of dysphagia in each group.