Table 3

Instruments for measuring perceived adequacy of staffing (PAS), including characteristics and psychometric properties

Title—author	Country	Measurement aim	Items, formats, subscale	Measurement type	Quality of instrument/subscale development	Sample size	Structural validity		Internal consistency		Other measurement properties
							Meth. Quality	Rating	Meth. Quality	Rating	Yes/no	Specification	Meth. Quality	Rating
Adequate staff for care—Spence Laschinger56	Canada	To measure nurses' perceptions of adequate staffing to provide high quality of nursing care.	Single item, item not reported	Possible score range 1–5	Inadequate	NR	NA	NA	NA	NA	No	NA	NA	NA
American Association of Critical-Care Nurses Healthy Work Environment (AACN-HWE) Assessment Tool50	USA	To assess the health of the work environment.	Subscale Appropriate staffing, 3 items: Administrators and nurse managers work with nurses and other staff to make sure there are enough staff to maintain patient safety Administrators and nurse managers make sure there is the right mix of nurses and other staff to ensure optimal outcomes Support services are provided at a level that allows nurses and other staff to spend their time on the priorities and requirements of patient and family care	5-point Likert Scale (strongly disagree–strongly agree)	Inadequate	500	Inadequate	NR	Very good	+ α>0.80	Yes	Hypothesis testing	Inadequate	NR OOM
Assessment of real-time demand for the emergency department (ED)—Reeder, Burleson, and Garrison54	USA	To assess the current real-time demands for the ED	Single item; Are the demands on current resources significantly greater than your available resources?	Exceeded/not exceeded	Inadequate	NR	NA	NA	NA	NA	No	NA	NA	NA
Head nurse questionnaire - Trivedi and Hancock43	USA	To measure and predict workload on nursing units using perceptions of head nurses	Nursing workload, 6 items: (Q1) If one additional person was available to you on your unit for today’s shift: How would you express the need for that person if that person was an (1) RN (2) LPN (3) aide? (Q3) If one person had been withdrawn from your unit for staffing elsewhere: With what degree of difficulty could you have released that person if that person was an (4) RN (5) LPN (6) aide?	5-point Likert Scale (no need–very great need) 5-point Likert Scale (very great difficulty–no difficulty)	Doubtful	For the day shift, the head nurse of five study units completed the questionnaire for a 7-week period	NA	NA	NA	NA	No	NA	NA	NA
Hospital Survey on Patient Safety Culture (HSOPS) —Sorra & Nieva55	USA	To assess the culture of patient safety in healthcare organisations	Subscale Staffing, 4 items; (A2) We have enough staff to handle the workload (A5) Staff in this unit work longer hours than is best for patient care (negatively worded) (A7) We use more agency/temporary staff than is best for patient care (negatively worded) (A14) We work in ‘crisis mode’ trying to do too much, too quickly (negatively worded)	5-point Likert Scale (strongly disagree–strongly agree)	Doubtful	1437	Very good	+EFA and CFA loadings NR, CFI≥0.90, RMSEA 0.04	Very good	- α 0.63	Yes	Hypothesis testing Hypothesis testing	Doubtful Doubtful	+OOM ? KG
MISSCARE Survey—Kalisch and Williams38	USA	MISSCARE Survey: to measure missed nursing care	Single item, part of unit and staff characteristics; % of the time perceived staffing adequacy in the unit	5-point Likert Scale 100% of the time (1), 75% of the time (2), 50% of the time (3), 25% of the time (4), 0% of the time (5)	Inadequate	NR	NA	NA	NA	NA	No	NA	NA	NA
New graduates’ perception of adequate staffing—Pineau Stam et al46	Canada	To measure new graduates’ perceptions of adequate staffing for the successful provision of care	Single item; In the last month how often has short staffing affected your ability to meet your patient/clients' needs?	5-point Likert Scale (1=never, 2=monthly, 3=weekly, 4=several times a week, 5=daily)	Inadequate	NR	NA	NA	NA	NA	No	NA	NA	NA
Nurse-perceived staffing adequacy—Cho et al87	South Korea	To measure nurse-perceived staffing adequacy	Single item; Was there a sufficient number of nurses to provide quality nursing care on the unit?	4-point Likert Scale (very insufficient–very sufficient)	Inadequate	NR	NA	NA	NA	NA	No	NA	NA	NA
Nursing Teamwork Survey—Kalisch et al48	USA	To measure levels of nursing teamwork in acute care settings	Single item, part of unit and staff characteristics; % of the time perceived staffing adequacy in the unit	5-point Likert Scale 100% of the time (1), 75% of the time (2), 50% of the time (3), 25% of the time (4), 0% of the time (5)	Inadequate	NR	NA	NA	NA	NA	No	NA	NA	NA
Nursing Work Index - Extended Organisation (NWI-EO)—Bonneterre et al61	France	To assess perceived levels of stress caused by psychosocial and organisational work factors	Subscale Staffing inadequacy to perform duties, 2 items: Enough registered nurses on staff to provide quality patient care Enough staff to get the work done	4-point Likert Scale (strongly agree–strongly disagree)	Doubtful	4085	Adequate	−EFA loadings NR	Very good	+α 0.89	Yes	Reliability Hypothesis testing	Doubtful Doubtful	- Spearman’s r 0.61 ? KG
Nursing Work Index - Revised (NWI-R)—Aiken and Patrician34	USA	To measure characteristics of professional nursing practice environments	No staffing subscale derived in original study34	4-point Likert Scale (strongly agree–strongly disagree)	NA	NA	NA	NA	NA	NA	NA
PAS Scale (part of essentials of magnetism II)—Kramer and Schmalenberg11	USA	To measure perceived adequacy of staffing as a process variable	Subscale Perceived adequacy of staffing, 6 items; Adequate to give quality patient care Adequacy varies with/is affected by type of delivery system Inadequate even if all budgeted positions are filled Adequate for safe patient care Cohesiveness and teamwork help Positively affects job satisfaction	4-point Likert Scale	Adequate	729	Adequate	−EFA loadings 0.549–0.711	Very good	+α 0.873	Yes	Hypothesis testing	Adequate	+KG
Perceived Nursing Work Environment (PNWE)—Choi et al51	USA	To measure the perceived work environment for critical care practice	Subscale Staffing and resources adequacy, 5 items; Enough staff to get the work done Enough RNs to provide quality patient care Adequate support services allow me to spend time with my patients Enough time and opportunity to discuss patient care problems with nurse A satisfactory salary	4-point Likert Scale (strongly agree–strongly disagree)	Doubtful	2324	Adequate	−EFA loadings 0.47–0.80	Very good	+α 0.83	Yes	Hypothesis testing Hypothesis testing	Doubtful Adequate	+OOM −KG
Perception of staffing adequacy—Cho et al86	Korea	To measure perceptions of staffing adequacy	Single item; Enough nurses to provide high-quality nursing care	4-point Likert Scale (strongly agree–strongly disagree)	Inadequate	NR	NA	NA	NA	NA	No	NA	NA	NA
Perception of work conditions—Gerolamo36	USA	To measure nurses' perceptions of the working conditions on their unit	Single item of perceived adequacy of staffing; We had enough staff this shift to handle the workload	5-point Likert Scale (strongly agree–strongly disagree)	Inadequate	NR	NA	NA	NA	NA	No	NA	NA	NA
Perceptions of adequacy of staffing—Mark, Salyer, and Harless58	USA	To measure perceptions of staffing adequacy	Single item; Evaluate the adequacy of staffing on your unit	5-point Likert Scale (very much above average–very much below average)	Inadequate	NR	NA	NA	NA	NA	No	NA	NA	NA
Perceptions of understaffing— Weigl, Schmuck, Heiden, Angerer, and Müller82	Germany	To measure perceived staffing level on the ward or hospital unit	Single item; Staffing level is sufficient in this unit/ward	5-point Likert Scale (no, not at all, yes, to a very great extent)	Inadequate	NR	NA	NA	NA	NA	No	NA	NA	NA
Practice Environment Scale of the Nursing Work Index (PES-NWI)—Lake41	USA	To measure the hospital nursing practice environment	Subscale Staffing and resource adequacy, 4 items: Enough staff to get the work done Enough RNs to provide quality patient care Adequate support services allow me to spend time with my patients Enough time and opportunity to discuss patient care problems with other nurses	4-point Likert Scale	Adequate	2299	Adequate	? EFA loading 0.47–0.73	Very good	+α 0.80	Yes	Reliability Hypothesis testing	Adequate Very good	+ICC 0.96 +KG
Professional Assessment of Optimal Nursing Care Intensity Level (PAONCIL)—Fagerström and Rainio64	Finland	To assess the nursing care intensity of a ward, that is, the degree to which personnel resources are in balance with the patients' care needs	Professional estimate of the nursing care intensity, single item; Assess the nursing intensity of the patients you nursed during your shift	7-point scale from −3 (very low) to +3 (very high) The estimate can be made with an accuracy of 0.25 points	Inadequate	169	NA	NA	NA	NA	Yes	Hypothesis testing	Adequate	+OOM
Unit staffing/care evaluation form —Williams and Murphy44	USA	To obtain charge nurses' evaluations of staffing adequacy and levels of direct care provided	Single item; In general, did you feel that staffing for this shift was:	4-point Likert Scale (more than adequate–inadequate)	Inadequate	NR	NA	NA	NA	NA	No	NA	NA	NA
Workload Perceptions Survey—Hegney et al91	Australia	To measure adequacy of staffing to meet patient needs	Relevant questions; (Q20) Were sufficient staff employed in your work unit to meet patient/client/resident needs? (Q21) Was the skill mix of nursing/midwifery staff employed in your work unit adequate to meet the daily needs of patients/clients/relatives?	5-point Likert Scale (never or very seldom–always or nearly always)	Inadequate	NR	NA	NA	NA	NA	No	NA	NA	NA

.CFA, confirmative factor analysis; CFI, Comparative Fit Index; EFA, exploratory factor analysis; ICC, intraclass correlation coefficient; KG, known groups; LPN, licensed practical nurse; NA, not applicable; NR, not reported; OOM, other outcome measurement; RMSEA, root mean square error of approximation; RN, registered nurse.