Table 5. Overall studies reporting on prevalence (%) of health anxiety by chronic illness.

Disease (k)	Mode of determination (k)	Range of prevalence	Author	Reported prevalence	Determination of prevalence scores
Cancer (58)		0–86
	Cut-off (20)	4.3–70	Aghdam et al., 2014 [31]	49.6	Scale literature on FoP-Q-SF for “high FoP”
			Anderson et al., 2014 [134]	8	Scale literature cut-off for MAX-PC for “clinical fear of recurrence”
			Butow et al., 2014 [32]	44	Scale literature on FCRI for “clinical fear of cancer recurrence”
			Custers et al., 2013 [135]	51	Scale literature on CWS for "high fear of recurrenc"
			Custers et al., 2014 [33]		ROC curve determing cut-off for high fear of recurrence for the CWS using 2-item CAS
				31	CWS
				40	CAS
			Dinkel et al., 2014 [35]	20	80th percentile on FoP-Q determined by authors
			Ghazali et al., 2013 [36]	35	Established algorithm on 7-item scale identifying “significant fear of recurrence”
			Halbach et al., 2016 [140]	16.9	1 SD above the mean on the FoP-Q-SF
			Hefner et al., 2016 [150]	16.2	1 SD above the mean on the FoP-Q-SF
			Hinz et al., 2015 [137]	16.7	Scale literature cut-off for FoP-Q-12
			Jones et al., 2014 [5]	23.4	Scale literature on SHAI for “clinically signifikant health anxiety”
			Lebel et al., 2013 [38]	58.3	Established in FCRI literature for “clinically elevated fear of cancer recurrence”
			Liu et al., 2011 [61]		Sclae literature cut-off for CARS
				24.8	Moderate
				4.3	High
			Mehnert et al., 2013 [41]	18.1	1 SD above the mean on the FoP-Q-SF
			Petzel et al., 2012 [45]	28–37	Established in FCRI literature for “fear of cancer recurrence”
			Rylands et al.,2016 [156]	23	Highest quartile on seven-item scale
			Sarkar et al., 2014 [47]	36	ROC curve analyses for determination of cut-off for "high fear of recurrence" on the FoP-Q-SF
			Savard & Ivers, 2013 [48]	44.0–56.1	Scale literature for FCRI “clinical levels of fear of cancer recurrence”
			Simard & Savard, 2015 [68]	42	Clinical level of fear of cancer recurrence identified by interview SIFCR
			Thewes et al., 2013 [52]	70	Scale literature for FCRI “clinical levels of fear of cancer recurrence”
	Item severity (23)	0–69.2	Cho et al., 2017 [138]		Items means at “somewhat” or “very much” on ASC subscale fear of recurrence
				36.1	Moderate to high
				13	High
			Cutshall et al., 2015 [147]	52	One item fear of cancer recurrence response "somewhat or a lot bothersome"
			De Padova et al., 2011 [139]		One item fear of cancer recurrence
				58	None/a little
				26	Quite a lot
				16	A lot
			De Vries et al., 2014 [34]		Responses to question "anxious about the possibility that the cancer may return":
				11	Not at all
				74	A little
				11	Somewhat
				0	A lot/very much
			Fang et al., 2017 [148]	48	VAS used to identify "moderate" to "high" fear of cancer recurrence
			Fisher et al., 2016 [149]	50	"Agree" or "strongly agree" on the item "have fear about my cancer coming back"
			Handschel et al., 2012 [146]		Responses to one item on fear of recurrence:
				19.5	Not at all
				30.1	Little
				27.9	Moderate
				16.1	Strong
				6.4	Very strong
			Janz et al., 2011 [151]		Mean on items assessing worry about recurrence:
				14	Not at all
				32	A little bit
				25	Somewhat
				16	Quite a bit
				14	Very much
			Jones et al., 2017 [58]		Response to item about worry about cancer coming back or getting worse
				16.2	Never
				24.5	Rarely
				39.7	Sometimes
				14.7	Often
				4.9	All the time
			Koch et al., 2014 [106]		Established on scale literature of FoP-Q-SF
				82	Low
				11	Moderate
				6	High
			Koch-Gallenkamp et al., 2016 [59]		Established on scale literature of FoP-Q-SF
				87	Low
				9	Moderate
				4	High
			Maguire et al., 2017 [62]		Score standardized 0 to 100
				61.0	Scoring above 25
				18.6	Scoring above 50
			Manne et al., 2016 [63]		Group-based trajectory model using CARS
				25.5	Low-stable
				25.3	High-decreasing
				49.1	High-stable
			Matthew et al., 2017 [152]		Responses to author designed 5-item scale
				36.8–62.2	Not at all
				48.8–51.2	Mild
				34.7–65.3	Moderate
				30.8–69.2	Severe
			Moye et al., 2014 [43]		Indicating "sometimes" to "always" for items:
				44	fear of cancer coming back
				32.5	fear of another cancer
				39	fear of future diagnostic tests
			Myers et al., 2013 [145]	47	"Moderate-to-high" recurrence fears endorsed on CARS
			Ness et al., 2013 [141]		Indicating severity on item on fear of recurrence:
				63	Any level
				17	Extreme
			O’Malley et al., 2017 [153]		Responses on single item on fear of cancer recurrence:
				12.3	Almost never
				17.9	Not very much
				45.9	Sometimes
				23.9	Very often
			Pedersen et al., 2012 [142]		Indicating severity on item on worry about risk of recurrence:
				47.2	A little
				19.3	Quite a bit
				8.5	Very much
			Rogers et al., 2016 [66]		New single item and 7-item scale assessing fear of recurrence
				12	Single item: No fear
				49	Single item: A little fear
				29	Single item: Sometimes having fearful thoughts
				5	Single item: A lot of fears
				5	Singel item: Fearful all the time
				8–23	7-item measure: "a lot" or "all the time"
			Rogers et al., 2017 [155]		Responses on single item measure on fear of recurrence:
				9.3	No fear
				42.0	A little fear
				34.6	Sometimes having fearful thoughts
				9.3	A lot of fear
				4.9	Fearful all the time
				10–19	Responses to seven item scale "a lot" or "all the time"
			Smith et al., 2016 [157]	30	Reporting "very much" or "quite a bit" of fear of recurrence on single item
			Tewari et al., 2014 [143]		Severity of score on frequency of worrying about cancer coming back:
				28.5	Rarely
				19.5	Sometimes
				5.2	Often
				1.9	Always
			Waters et al., 2013 [144]		Indicating on item “worried about progression”:
				69.8	Not at all
				16.0	A little
				10.4	Somewhat
				3.3	Quite a bit
				0.4	Very much
	No cut-off (11)	18–86	Befort et al., 2011 [158]	52	Yes/no to “any fear of recurrence” from checklist of symptoms
			Cheng et al., 2014 [162]	18	Reported unmet need of fears of cancer spreading
			Kanatas et al., 2013 [159]	33	Percentage of clinic appointments when fear of cancer coming back was mentioned
			Posluszny et al., 2016 [154]	86	"Yes"on at least one out of three yes/no items
			Schlairet, 2011 [160]	73.2	Participants identifying “fear of recurrence”
			Scott et al., 2013 [161]	25–52	Self-report for “any fear of cancer recurrence”
			Shay et al., 2016 [67]	85.2/79.7	Yes/no item on fear of recurrence in younger/ older cancer survivors
			Taylor et al., 2012 [49]	67	Minimal possible score of “at least some fear of recurrence”
			Van Liew et al., 2012 [136]	60.1	“Clinically significant levels of fear of recurrence” using FCRI with cut-off not reported
			van Londen et al., 2014 [163]	67	Yes/no fear of cancer recurrence identified as concern
			Wells et al., 2015 [164]	48	Report concerns of fear of cancer recurrence
	Not specified (3)	51–80	Moretto et al., 2014 [165]	80	Unspecified fear of recurrence
			Naidoo et al., 2013 [166]	69	Unclear fear of recurrence
			Pandya et al., 2011 [167]	51	Unspecified feared recurrence
Cardiac diseases (8)		11–48.6
	Cut-off (2)	31–48.6	Bunz et al., 2016 [98]	48.6	90th percentile of CAQ score in the general population
			Hoyer et al., 2008 [90]	31	2 SD above the mean of the non-cardiac comparison group for “clinically elevated cardiac anxiety” on CAQ
	Item severity (5)	11–19	Koivula et al., 2010 [171]		"High" fear on CHDPF items for fear of:
				19	Uncertainty about illness
				15	Deterioration of coronary heart disease
				12	Myocardial infarction
			Pauli et al., 1999 [173]		Fear of dying before AICD implantation:
				59	None
				23	Some
				18	Definite
			Rosman et al., 2015 [99]		"Often" or "always" on CAQ items:
				17.6	If tests come out normal, I still worry about my heart.
				14.6	I worry that I may have a heart attack.
			Schuster et al., 1998 [172]		Fear of death identified in concerns list:
				62	None
				18	Slight
				10	Moderate
				3	Quite a bit
				8	Extreme
			van Beek et al., 2012 [96]		Groups identified by latent class analysis
				30.4	Continuously low
				45.4	Continuously medium
				7.7	Continuously high
				16.5	High-decreasing
	No cut-off (1)	16.6	Pollack et al., 2005 [174]	16.6	Clinically relevant heart-focused anxiety on CAQ
	Unspecified (0)
COPD (2)		14–94.3
	Cut-off (0)
	Item severity (1)	14	Stenzel et al., 2012 [168]		Mean on items assessing worry about recurrence:
				35	No at all
				34	Slightly
				17	Moderate
				14	Strong/very strong
	No cut-off (1)	94.3	Heffner et al., 1996 [169]	94.3	Identified health concern among many concerns
Diabetes (13)		0–81
	Cut-off (9)	0–81	Anarte Ortiz et al., 2011 [30]		ROC curve analyses on FH-15 for “fear of hypoglycemia” using single item as criterion
				45.4	FH-15
				48.0	Single item
			Belendez et al., 2009 [15]	33	Unclear cut-off on HFS for "being worried about developing hypoglycaemia"
			Claude et al., 2014 [7]	24.1	Established in literature of SHAI for “elevated health anxiety”
			Cox et al., 1998 [195]		2 SD above published mean in worry scale of HFS
				2	Normally sighted
				0	Partially sighted
				19	Totally blind
			Hajos et al., 2014 [196]		Four criteria to establish cut-off for “clinical fear of hypoglycemia” on HFS worry scale
				81	Modal distribution criterion
				5	SD criterion
				31/21	Concurrent validity criterion
				26	Elevated item endorsement criterion
			Majanovic et al., 2017 [197]	11.1	Establisthed algorithm on elevated item endorsement on HFS-II worry subscale
			Nixon & Pickup, 2011 [198]	27	Score > 50% of total possible score “substantial fear of hypoglycemia”
			Shiu & Wong, 2000 [199]	15	Cut-off > 30 on HFS for "high fear of hypoglycemia"
			van Beers et al., 2017 [204]	25	1 SD above mean in worry scale of HFS
	Item severity (2)	27.7–77	Martyn-Nemeth et al., 2017 [200]		HFS for assessment of "trait fear of hypglycemia" and daily-diary recorded fear of hypoglycaemia
				51	Worry becoming hypoglycemic while sleeping
				77	High daily fear (score 4/5 on two 1–5 items) at least once during six-day study period
			Sakane et al., 2015 [203]	27.7	"Fear of hypoglycemia" was defined as the highest quintile on single item
	No cut-off (1)	30	Myers et al., 2007 [201]	30	HFS "fear of death from hypoglycemia"
	Unspecified (1)	62.9	Riaz et al., 2014 [202]	62.9	Reported “fear of hypoglycemia”
Epilepsy (1)		45.5
	Cut-off (0)
	Item severity (0)
	No cut-off (1)
	Unspecified (0)	45.5	Mameniskiene et al., 2015 [205]	45.5	Constant fear of the next seizure
Hepatitis (1)		25–44
	Cut-off (0)
	Item severity (0)
	No cut-off (1)	25–44	Alizadeh et al., 2008 [194]		Prinicipal concern:
				25	Developing liver cancer
				44	Disease progression to cirrhosis
	Unspecified (0)
HIV/AIDS (2)		9.4–76.2
	Cut-off (0)
	Item severity (1)		Sarna et al., 1999 [132]	76.2	Indicating "a fair amount" to "very much" on item "worry whether HIV is progressing"
	No cut-off (1)		Kemppanien et al., 2003 [133]		Any indication of "fealing anxious":
				9.4	About the onset of new symptoms
				18.9	About death
Multiple sclerosis /neuromuscular disorders (4)		24.9–63.5
	Cut-off (3)	24.9–60.3	Kalron & Achiron, 2014 [102]		Results of ROC analysis of FES-I in another study identifying fear of falling
				39.7	Slightly concerned
				60.3	Highly concerned
			Kehler et al., 2009 [175]	24.9	Scale literature of SHAI for “elevated health anxiety”
			Pieterse et al., 2006 [179]	58	Scale literature of FES for “fear of falling”
	Item severity (1)	63.5	Peterson et al., 2007 [192]	63.5	Yes/no to question "are you concerend about falling"
	No cut-off (0)
	Unspecified (0)
Parkinson’s disease (22)		7–89
	Cut-off (7)	25–48	Allen et al., 2012 [176]	45.7	Scale literature of FES-I for “high fear of falling"
			Bryant et al., 2014 [71]	44.3	Established in literature for ABC “high fear of falling”
			Chomiak et al., 2015 [177]	25	Scale literature of FES-I for "high fear of falling"
			Franzen et al., 2016 [78]		Scale literature of FES-I for fear of falling
				12	Low
				39	Moderate
				48	High
			Jonasson et al., 2015 [79]		Scale literature on FES-I for levels of fear of falling
				29	Low
				58	Moderate
				47	High
			Landers et al., 2014 [178]	46.4	Cut-off ≥20 on FABQ for "fear of falling avoidance behavior"
			O’Connell & Guidon, 2016 [82]	45.2	Scale literature of ABC for “high fear of falling"
	Item severity (1)	14	Grimbergen et al., 2013 [180]		Single item on fear of falling
				41	No
				45	Somewhat
				14	Very
	No cut-off (10)	35–89	Combs et al., 2014 [181]	44	Yes/no to feeling worried about falling
			Dennison et al., 2007 [182]	35	Yes/no to item “any fear of falling”
			Jonasson et al., 2014 [183]	55	Yes/no to item “fear of falling”
			Kader et al., 2016 [184]	48	Yes/no to item "are you afraid of falling"
			Kataoka et al., 2011 [185]	83	Present or not at any level “fear of falling”
			Lindholm et al., 2014 [73]	37	Yes/no to item “any fear of falling”
			Nilsson et al., 2010 [74]	43	Yes/no to item “fear of falling”
			Nilsson et al., 2010 [186]	38	Yes/no to item “fear of falling”
			Nilsson et al., 2012 [75]	45	Yes/no to item “fear of falling”
			Thomas et al., 2010 [187]	89	At least some fear of falling on FES
	Unspecified (4)	7–83.7	Bloem et al., 2001 [188]	45.8	Any fear of falling indicated in clinical interview
			Cubo et al., 2012 [189]	53	Fear of falling assessed with structured questionaires and ABC
			Lindholm et al., 2015 [190]	83.7	Not specified
			Pasman et al., 2011 [191]	7–15	Not specified: fear of falling during three experimental conditions
Stroke (3)		7.4–56
	Cut-off (1)	19	Guan et al., 2015 [170]	19	ABC scale cut-off from validation literature of healthy population
	Item severity (2)	7.4–56	Noble et al., 2011 [105]		Reporting "Extremely fearful" on single item “fear of another haemorrhage”
				7.4	Patients without PTSD
				32.1	Patients with PTSD
			Townend et al., 2006 [193]	56	"Agree"/"strongly agree" on item “worry about my stroke returning”
	No cut-off (0)
	Unspecified (0)

In articles that reported longitudinal outcomes, we have reported the baseline findings. Among item severity scores, we have indicated the range of prevalence of highest possible scores.

ABC = Activities-specific Balance Confidence Scale; ASC = Assessment of Survivor Concerns; AICD = Automatic Implantable Cardioverter Defibrillator; CHDPF = Coronary Heart Disease Patients Fear Scale; CARS = Concerns About Recurrence Scale; CAS = Cancer Acceptance Scale; CAQ = Cardiac Anxiety Questionnaire; CWS = Cancer Worry Scale; FABQ = Fall Avoidance Behaviour Questionnaire; FCRI = Fear of Cancer Recurrence Inventory; FES = Falls Efficacy Scale; FES-I = Falls Efficacy Scale–International; FH-15 = Fear of Hypoglycemia 15-item Scale; FoP-Q-SF = Fear of Progression Questionnaire-Short Form; HFS = Hypoglycemia Fear Survey; MAX-PC = Memorial Anxiety Sclae for Prostate Cancer; PTSD = Posttraumatic Stress Disorder; ROC = Receiver operating characteristic; SD = standard deviation; SHAI = Short Health Anxiety Inventory; SIFCR = Semi-Structured Interview on Fear of Cancer Recurrence; VAS = Visual Analogue Scale