Assigning Clinical Significance and Symptom Severity Using the Zung Scales: Levels of Misclassification Arising from Confusion between Index and Raw Scores

Table 3

Articles and evaluation of the use of the Zung Self-Rating Depression Scale (SDS) and Self-Rating Anxiety Scale (SAS).

Reference details	Discipline	SDS				SAS
		Used?	Cut-off	Severity range	Notes	Used?	Cut-off	Severity range	Notes
2010
Chagas et al., 2010 [16]	Neuroscience	✓	2	5
Friebe et al., 2010 [17]	Psychiatry	✓	2	2
Lande et al., 2010 [18]	Psychiatry	✓	2	2
Saban et al., 2010 [19]	Psychiatry					✓	5	5
Ohira, 2010 [20]	Cardiovascular	✓	1	5
Lombardi et al., 2010 [21]	Immunology	✓	5	5
Podlipný et al., 2010 [22]	Psychiatry	✓	2	2
Ostojic et al., 2010 [23]	Rheumatology					✓	2	2	“SAS” severity ranges
Sonikian et al., 2010 [24]	Nephrology	✓	3	3
Biggs et al., 2010 [25]	Psychiatry	✓	3	5
Alimohammadi et al., 2010 [26]	Health					✓	5	5
Oishi et al., 2010 [27]	Audiology	✓	1	5	Cut-off of 48 used (i.e., index of 60)
Bitsika et al., 2010 [28]	Counselling					✓	1	5
Sharpley et al., 2010 [29]	Oncology					✓	1	5
Klemenc-Ketiš et al., 2010 [30]	Mental health					✓	1	5	Cut-off of 50 raw score
Tang et al., 2010 [31]	Mental health					✓	5	5
Fernandes et al., 2010 [32]	Psychometrics					✓	1	1	Raw score ranges: up to 36 - no anxiety. 37–39 - possible anxiety: 40+ - high anxiety.
Wang et al., 2010 [33]	Urology					✓	2	5	cut-off 50 (Chinese)
Pascazio et al., 2010 [34]	Nephrology					✓	5	5
Herbert et al., 2010 [35]	Psychology	✓	3	3
2011
Ide, 2011 [36]	Orthopedic	✓	1	1
Lande et al., 2011 [37]	Psychiatry	✓	5	5
Li et al., 2011 [38]	Psychology	✓	5	5	Short 10-item version of SDS used
Huang et al., 2011 [39]	Cardiology	✓	4	4	Used index classifications with no indication of conversion
Takayama et al., 2011 [40]	Dentistry	✓	1	1	Mentions index conversion but uses raw scores correctly
Perugi et al., 2011 [41]	Psychiatry	✓	4	4	Used index scores with no indication of conversion	✓	4	4	Used index scores with no indication of conversion: cut-off of 50. SDS ranges
Ogawa et al., 2011 [42]	Gynecology	✓	5	5
Uji et al., 2011 [43]	Psychotherapy	✓	5	5	Only used 7 statements: “affective subscale”
Davidson et al., 2011 [44]	Psychology					✓	5	5
Sharpley et al., 2011 [45]	Oncology	✓	1	5	SAS cut-off
Wan et al., 2011 [46]	Psychiatry					✓	5	5
Weigold and Robitschek, 2011 [47]	Psychiatry					✓	5	5
Li et al., 2011 [48]	Opthalmology					✓	2	5	Chinese cut-off used (50 index)
Liao et al., 2011 [49]	Drugs					✓	5	5
Nassiri et al., 2011 [50]	Env. science					✓	4	4	Divided into normal/low/moderate/high but no indication given of cut-offs or indexing
De Tommaso et al., 2011 [51]	Neurology					✓	5	5
Chiaffarino et al., 2011 [52]	Gynecology					✓	1	1	Raw score ranges: <40, nonanxious; 40–60 anxious symptoms; >60 clinically significant anxiety
Richards et al., 2011 [53]	Psychology	✓	4	4	Uses Index scores: no mention of conversion	✓	4	4	Uses index scores with no mention of conversation. “SAS” ranges
2012
Yu et al., 2012 [54]	Cardiology	✓	2	2		✓	2	2	“SAS” severity ranges
Lei et al., 2012 [55]	Psychiatry	✓	2	5	Chinese cut-offs used (53 index)	✓	2	5	Chinese cut-off used (50 index)
Mammadova et al., 2012 [56]	Psychiatry	✓	5	5	Calculating appropriate cut-off for different population
Trento et al., 2012 [57]	Endocrinology	✓	3	3		✓	3	3	“SAS” severity ratings
Adogwa et al., 2012 [58]	Orthopaedics	✓	3	5
Gao et al., 2012 [59]	Psychiatry					✓	1	5	Use Chinese norm cut-off of 40 (raw score)
Sawa et al., 2012 [60]	Psychiatry	✓	5	5
Chang and Koh, 2012 [61]	Mental health	✓	5	5
Sapranaviciute et al., 2012 [62]	Psychology	✓	5	5
de Pasquale et al., 2012 [63]	General medicine	✓	3	5		✓	5	5
Shen et al., 2012 [64]	Psychiatry					✓	2	5	Chinese cut-off: index 50
Liu et al., 2012 [65]	Gastroenterology					✓	2	5	Probably used Chinese cut-off
Huang et al., 2012 [66]	Gynecology					✓	2	5	Chinese cut-off: index 50
Li et al., 2012 [67]	Mental health					✓	5	5
Tang et al., 2012 [68]	Gastroenterology					✓	5	5
Campbell et al., 2012 [69]	Psychiatry	✓	5	5
2013
Adogwa et al., 2013 [70]	Spinal	✓	3	5	Other ranges used based on quartiles
Balázs et al., 2013 [71]	Psychology					✓	4	4	“SAS” severity ranges
Li et al., 2014 [72]	Oncology	✓	1	5	Chinese cut-offs used (42 raw)
Lowery et al., 2013 [73]	Psychiatry	✓	5	5	Brief instrument used. Score range indicated index scores (25 to 100) but only raw range given (1 to 4 Likert)	✓	5	5	Score range indicated index scores (25 to 100) but only raw range given (1 to 4 Likert)
Zhang et al., 2013 [74]	Urology	✓	2	5
Guo et al., 2013 [75]	Oncology	✓	2	5	Chinese version used	✓	2	5	Chinese cut-off used
Nardelli et al., 2013 [76]	Neurology	✓	3	5
Siennicki-Lantz et al., 2013 [77]	Geriatric	✓	2	2	SAS “severity rating” applied (i.e., mild depression 45–59)
Liu et al., 2013 [78]	Immunology					✓	2	5	Chinese cut-off used
Deb, 2013 [79]	Pharmacology	✓	3	3		✓	3	3	SAS “severity ratings”
Wang et al., 2013 [80]	Psychiatry	✓	2	5	Chinese version used
Khorvash et al., 2013 [81]	Neuroscience					✓	4	4	“SAS” severity ratings provided
Quintão et al., 2013 [82]	Psychology					✓	5	5
Delibegovic and Sinanovic, 2013 [83]	Oncology	✓	4	4		✓	4	4	Uses SDS severity ratings
Klemenc-Ketiš and Peterlin, 2013 [84]	Psychiatry	✓	3	3
Carli et al., 2013 [85]	Public health					✓	5	5	“A full description of assessment instruments and interventions was previously published”
Grandi et al., 2013 [86]	Gynecology	✓	5	5	“Higher scores indicating worst depressive symptoms.” Raw score range given (20 to 80)
Luo et al., 2013 [87]	Geriatric					✓	5	5
2014
Akinsulore et al., 2014 [88]	Psychology	✓	2	2
Banth and Sharma, 2014 [89]	Psychology	✓	3	3
Bhatti et al., 2013 [90]	Spinal					✓	3	3	“SAS” severity ranges
Kaess et al., 2014 [91]	Psychiatry					✓	4	4	“SAS” severity ranges
Atteritano et al., 2014 [92]	Gynecology	✓	3	3
Lee et al., 2014 [93]	Endocrinology	✓	5	5	“Severity score was calculated by formula conversion” and link to Zung article
Vlachos et al., 2014 [94]	Gastroenterology	✓	3	5
Ding et al., 2014 [95]	Psychiatry					✓	1	5	Chinese cut-off used (40 raw)
Trento et al., 2014 [96]	Endocrinology					✓	3	3	“SAS” severity ranges
Fernández‐Matarrubia et al., 2014 [97]	Neurology	✓	5	5		✓	5	5
Feng et al., 2014 [98]	Public health	✓	4	5	Chinese cut-offs used (53 index)	✓	4	5	Chinese cut-offs used (50 Index)
Hou et al., 2014 [99]	Nephrology	✓	2	5	“Each scale consists of 40 items,”- incorrect description of scales provided. Chinese version used: non-Chinese cut-off	✓	2	5	“Each scale consists of 40 items,” incorrect description of scales provided. Chinese version used: Chinese cut-off
Khorvash et al., 2014 [100]	Neurology					✓	5	5
Liu et al., 2014 [101]	Respiratory	✓	4	5	Chinese version used	✓	4	5	Chinese cut-off used
La Fianza et al., 2014 [102]	Radiology	✓	1	5		✓	1	5	`
2015
Bobić et al., 2015 [103]	Psychiatry	✓	1	5	Chinese cut-offs used (42 raw)
Chen et al., 2015 [104]	Orthopedic	✓	4	5	Chinese cut-offs used (53 index)	✓	4	5	Chinese cut-off used (50 index)
Jiang et al., 2015 [105]	Rheumatology	✓	5	5		✓	5	5
Rus Makovec et al., 2015 [106]	Public health	✓	2	2		✓	2	2	SDS severity ranges used
Kourkoveli et al., 2015 [107]	Cardiac	✓	1	5
Shi et al., 2015 [108]	Psychiatry					✓	2	5	Chinese cut-off used (50 index)
Stefanidou et al., 2015 [109]	Psychiatry	✓	3	5
Pozzi et al., 2015 [110]	Psychiatry					✓	5	5
Yuan et al., 2015 [111]	Neurology					✓	3	5	Chinese cut-off used (50 index)
Yin et al., 2015 [112]	Psychiatry	✓	3	3	SAS severity ranges quoted but Chinese cut-offs used (53 index)	✓	3	3	“SAS” severity ranges quoted but Chinese cut-off used (50)
Li et al., 2015 [113]	Spinal	✓	3	3	SDS standard indices applied to raw scores	✓	3	3	SDS severity ranges applied to raw scores
Hirao, 2015 [114]	Occupational therapy	✓	5	5	Mentioned the Japanese version
Lou et al., 2015 [115]	Cardiac					✓	2	2	Chinese cut-off used (50 index): ranges: 50–59; 60–69; 70+
Yang et al., 2015 [116]	Psychiatry	✓	2	5	Mentioned the Chinese version but used standard index cut-off (50)
Trento et al., 2015 [117]	Endocrinology					✓	3	3	“SAS” severity ranges

Notes. Zung analysis classifications; 1: consistent use of raw scores; 2: consistent use of index scores; 3: inconsistent application; 4: unclear whether consistent or not; 5: not utilized.