| Literature DB >> 30519001 |
Rob Ab Oostendorp1,2,3,4, Hans Elvers5,6, Emiel van Trijffel7,8, Geert M Rutten9,10, Gwendolyne Gm Scholten-Peeters11, Marcel Heijmans4, Erik Hendriks12,13, Emilia Mikolajewska14,15, Margot De Kooning3,8,16, Marjan Laekeman17, Jo Nijs3,8,16, Nathalie Roussel18, Han Samwel19.
Abstract
PURPOSE: To develop valid quality indicators (QIs) for physiotherapy care based on best available evidence, and to use these QIs to explore trends in the quality of physiotherapy care of patients with Whiplash-associated disorders (WAD) using guideline-based routinely collected data (RCD) gathered between 1996 and 2011.Entities:
Keywords: Whiplash-associated disorders; clinical guidelines; clinical reasoning process; quality indicators; quality of physiotherapy care; routinely collected data
Year: 2018 PMID: 30519001 PMCID: PMC6233472 DOI: 10.2147/PPA.S179808
Source DB: PubMed Journal: Patient Prefer Adherence ISSN: 1177-889X Impact factor: 2.711
Figure 1Formula for frequency of indicator (∑I = sum scores of items per indicator, N = number of items per indicator, and N = number of respondents per year).
Figure 2Number of referrals per year 1996–2011 (N = 810).
Diagnostic process: differences between Group A 1996–2002 (n = 353) and Group B 2003–2011 (n = 457) regarding the clinical reasoning process in patients with Whiplash-associated disorders (WAD)
| Steps of diagnostic clinical reasoning process I–V | Total N = 810 | Group A 1996–2002 n = 353 | Group B 2003–2011 n = 457 | Difference |
|---|---|---|---|---|
| n (%) | n (%) | n (%) | ||
| General physician | 549 (67.8) | 262 (74.2) | 287 (62.8) | |
| Medical specialist | 164 (20.2) | 91 (25.8) | 73 (16.0) | |
| Self-referral (since 2005) | 97 (12.0) | – | 97 (21.2) | |
| Age (years) (mean, SD) | 43.0 (12.6) | 43.0 (11.6) | 43.2 (13.4) | NS |
| Gender (female) | 586 (72.3) | 244 (69.1) | 342 (74.8) | NS |
| Educational level (low) | 450 (55.6) | 192 (54.3) | 258 (56.5) | NS |
| Employment status (yes) | 510 (62.0) | 280 (79.3) | 230 (50.6) | NS |
| Direction of impact (back) | 512 (63.2) | 267 (75.6) | 248 (54.2) | |
| Anticipated collision (no) | 583 (72.0) | 222 (62.9) | 361 (79.0) | |
| Type of trauma | ||||
| Neck trauma without head trauma | 572 (70.6) | 275 (77.9) | 297 (65.0) | |
| Neck trauma with head trauma | 198 (24.4) | 74 (21.0) | 124 (27.1) | |
| Other trauma | 40 (4.9) | 4 (1.1) | 36 (7.9) | |
| Unknown | – | – | – | |
| Time of onset Whiplash-related complaints | ||||
| Immediately | 145 (17.9) | 43 (12.2) | 102 (22.3) | |
| ≤2 days | 556 (68.9) | 279 (79.0) | 277 (60.6) | |
| 3–7 days | 109 (13.5) | 31 (8.8) | 78 (7.9) | |
| >1 week | – | – | – | |
| Functioning problems | ||||
| Activity limitation (yes) | 125 (15.4) | 40 (11.3) | 85 (18.6) | |
| Participation problems (yes) | 109 (13.5) | 40 (11.3) | 69 (15.1) | NS |
| Job-related problems (yes) | 93 (11.5) | 36 (10.2) | 57 (12.5) | NS |
| Relevant medication use (yes) | 107 (13.2) | 39 (11.0) | 68 (14.9) | NS |
| Previous history of neck injury (yes) | 81 (10.0) | 33 (9.3) | 48 (10.5) | NS |
| Previous neck pain and stiffness (yes) | 144 (17.8) | 58 (16.4) | 86 (18.8) | NS |
| Pain else (yes) | 150 (15.8) | 44 (12.5) | 106 (23.2) | |
| Medical imaging neck diagnostics (yes) | 178 (22.0) | 96 (27.2) | 82 (17.9) | |
| Cervical soft collar (yes) | 514 (63.4) | 256 (72.5) | 258 (56.5) | |
| Weeks (mean, SD) | 3.9 (2.0) | 4.2 (2.4) | 3.7 (1.6) | |
| Pain medication (yes) | 369 (45.6) | 190 (53.8) | 179 (39.2) | |
| (Manual) physiotherapy (yes) | 332 (40.0) | 174 (49.3) | 158 (34.6) | |
| Functioning problems | ||||
| Impairments in musculoskeletal neck functions (yes) | 810 (100) | 353 (100) | 457 (100) | – |
| Activity limitation (yes) | 688 (84.9) | 273 (77.3) | 415 (90.8) | |
| Participation problems (yes) | 712 (87.9) | 288 (81.6) | 424 (92.8) | |
| Job-related problems (yes) | 312 (38.5) | 198 (84.4) | 114 (24.9) | |
| Pain medication (yes) | 242 (29.9) | 138 (39.1) | 104 (22.8) | |
| Type and number of complaints | ||||
| ≤3: neck pain, stiffness, decreased ROM | 6 (0.7) | 6 (1.7) | – | |
| 4–6: + dizziness, headache and tinnitus | 374 (46.2) | 249 (70.9) | 125 (27.4) | |
| 7–9: + cognitive impairments | 424 (52.3) | 96 (27.2) | 328 (71.8) | |
| >9: + rest | 6 (0.7) | 2 (0.6) | 4 (0.9) | |
| Inventory prognostic factors (modified Waddell’s sign; since 2001; n = 575) | ||||
| ≤3 | 45 (7.8) | 45 (38.1) | – | |
| >3 | 530 (92.2) | 73 (61.9) | 457 (100) | |
| Use of coping | ||||
| Active | 329 (40.7) | 173 (49.0) | 156 (34.1) | |
| Inestimable | 38 (3.7) | 37 (10.5) | 1 (0.2) | |
| Passive | 443 (54.7) | 143 (40.5) | 300 (65.6) | |
| Fear avoidance | ||||
| No | 146 (18.2) | 79 (22.4) | 67 (14.7) | |
| Inestimable | 197 (24.3) | 100 (28.3) | 97 (21.2) | |
| Yes | 467 (57.7) | 174 (49.3) | 293 (64.1) | |
| Presence of signs of central sensitization (since 2009; n = 149) | – | |||
| No | 7 (4.7) | 7 (4.7) | ||
| Inestimable | 76 (51.0) | 76 (51.0) | ||
| Yes | 66 (44.3) | 66 (44.3) | ||
| Objectives of musculoskeletal examination (yes) | 810 (100) | 353 (100) | 457 (100) | – |
| Objectives of neurological examination (yes) | 136 (16.8) | 63 (17.8) | 73 (16.0) | NS |
| Objectives of otoneurological examination (since 2000; n = 621) (yes/no) | 377 (60.7)/244 (39.3) | 64 (39.0)/100 (61.0) | 313 (68.5)/144 (31.5) | |
| Objectives of psychological examination (since 2000; n = 621) (yes/no) | 577 (92.9)/44 (7.1) | 133 (81.1)/31 (18.9) | 444 (97.2)/13 (2.8) | |
| Musculoskeletal examination | – | |||
| Observation of posture (yes) | 810 (100) | 353 (100) | 457 (100) | |
| Active examination of neck function (yes) | 810 (100) | 353 (100) | 457 (100) | |
| Passive examination of neck function (yes) | 810 (100) | 353 (100) | 457 (100) | |
| Palpation of tender points (yes) | 810 (100) | 353 (100) | 457 (100) | |
| Neurological examination | ||||
| Sensory testing (yes) | 136 (16.8) | 63 (17.8) | 73 (16.0) | NS |
| Motor testing (yes) | 130 (16.0) | 63 (17.8) | 67 (14.7) | NS |
| Reflex testing (yes) | 130 (16.0) | 63 (17.8) | 67 (14.7) | NS |
| Coordination testing (yes) | 91 (11.2) | 54 (15.3) | 37 (8.1) | |
| Otoneurological examination (since 2000; n = 621) | ||||
| Standing tests (yes/no) | 346 (55.7)/275 (44.3) | 63 (38.4)/101 (61.6) | 283 (61.9)/174 (38.1) | |
| Walking tests (yes/no) | 366 (58.9)/255 (41.1) | 63 (38.4)/101 (61.6) | 303 (66.3)/154 (33.7) | |
| Dizziness tests (yes/no) | 376 (60.5)/245 (39.5) | 63 (38.4)/101 (61.6) | 313 (68.5)/144 (31.5) | |
| Nystagmus tests (yes/no) | 376 (60.5)/245 (39.5) | 63 (38.4)/101 (61.6) | 313 (68.5)/144 (31.5) | |
| Dix-Hallpike test (yes/no) | 21 (3.4)/600 (96.6) | 3 (1.8)/161 (98.2) | 18 (3.9)/439 (96.1) | NS |
| Psychological examination | ||||
| Observation of pain behavior and fear avoidance (since 2000; n = 621) (yes/no) | 577 (92.9)/44 (7.1) | 133 (81.1)/31 (18.9) | 444 (97.2)/13 (2.8) | |
| Use of coping questionnaire (since 2002; n = 523) | 495 (94.6)/28 (5.4) | 38 (57.6)/28 (42.4) | 457 (100)/– | |
| Use of fear avoidance questionnaire (since 2002; n = 523) | 495 (94.6)/28 (5.4) | 38 (57.6)/28 (42.4) | 457 (100)/– | |
| Classification WAD | ||||
| WAD 0 | – | – | – | |
| WAD 1 | 123 (15.2) | 85 (24.1) | 38 (8.3) | |
| WAD 2 | 555 (68.5) | 205 (58.1) | 350 (76.6) | |
| WAD 3 | 132 (16.3) | 63 (17.8) | 69 (15.1) | |
| WAD 4 | – | – | – | |
| Time phase since accident | ||||
| >7 days | 19 (2.3) | 9 (2.5) | 10 (2.2) | |
| 1–3 weeks | 140 (17.3) | 72 (20.4) | 68 (14.9) | |
| 4–6 weeks | 192 (23.7) | 99 (28.0) | 93 (20.4) | |
| 7–12 weeks | 183 (22.6) | 75 (21.2) | 108 (23.6) | |
| 3–6 months | 155 (19.1) | 33 (9.3) | 122 (26.7) | |
| >6 months | 121 (14.9) | 65 (18.4) | 56 (12.3) | |
| Recovery rate since accident | ||||
| Normal | – | – | – | |
| Inestimable | 369 (45.6) | 179 (50.7) | 190 (41.6) | |
| Delayed | 441 (54.4) | 174 (49.3) | 267 (58.4) | |
| Determination of health profile | ||||
| Profile A | – | – | – | |
| Profile B | 369 (45.6) | 179 (50.7) | 190 (41.6) | |
| Profile C | 441 (54.4) | 174 (49.3) | 267 (58.4) | |
| Prognostic factors related to recovery | ||||
| Observation pain behavior (since 2000; n = 621) (yes/no) | 577 (92.9)/44 (7.1) | 133 (81.1)/31 (18.9) | 444 (97.2)/13 (2.8) | |
| Modified Waddell’s sign (>3/≤3) | 530 (92.2)/45 (7.8) | 73 (61.9)/45 (38.1) | 457 (100) | |
| Use of passive coping (yes) | 443 (54.7) | 143 (40.5) | – | |
| Fear avoidance (yes) | 467 (57.7) | 174 (49.3) | 300 (65.6) | |
| Presence of signs of central sensitization (since 2009; n = 149) (yes) | 47 (41.5) | 18 (23.7) | 293 (64.1) | |
| Indication physiotherapy (yes) | 66 (44.3) | – | 29 (39.7) | – |
Notes:
P ≤ 0.05; NS, non significant; -, no statistics.
Modified Waddell’s signs: tenderness, stimulation, cervical Range of Motion (ROM), regional disturbance, and overreaction.
Psychological questionnaires: Fear Avoidance Beliefs Questionnaire (FABQ) and Pain Coping Inventory (PCI).
Classification: WAD 0: no neck symptoms, no physical sign(s); WAD 1: neck pain, stiffness or tenderness only, no physical sign(s); WAD 2: neck symptoms and musculoskeletal sign(s); WAD 3: neck symptoms and neurological sign(s); WAD 4: neck symptoms and fracture or dislocation;
Health Profile: Profile A: normal recovery, low intensity of pain, decreasing pain, increasing activities; Profile B: inestimable recovery, middle intensity of pain, persistent pain, persistent activity limitations; Profile C: delayed recovery, high intensity of pain, increasing pain, decreasing activities.
Therapeutic and evaluative process: differences between Group A 1996–2002 (n = 353) and Group B 2003–2011 (n = 457) regarding the clinical reasoning process in patients with Whiplash-associated disorders (WAD) N = 810; n (%) unless otherwise stated
| Steps of therapeutic and evaluative clinical reasoning process VI–IX | Total N = 810 | Group A 1996–2002 n = 353 | Group B 2003–2011 n = 457 | Difference |
|---|---|---|---|---|
| n (%) | n (%) | n (%) | ||
| Treatment goals | ||||
| Phase I: <7 days: reducing pain, providing information and explaining the functioning consequences and underlying pain mechanisms (n = 19) (yes/no) | 11 (57.9)/8 (42.1) | 2 (22.2)/7 (77.8) | 9 (90.0)/1 (10.0) | |
| Phase II | 82 (58.6)/58 (41.4) | 24 (33.3)/48 (66.7) | 58 (85.3)/10 (14.7) | |
| Phase IIIa (inestimable recovery): 4–6 weeks: see Phase II + increasing activities and participation (n = 17) (yes/no) | 12 (70.6)/5 (29.4) | 3 (60.0)/2 (40.0) | 9 (75.0)/3 (25.0) | |
| Phase IIIb (delayed recovery): 4–6 weeks: explaining underlying pain mechanisms, improving active coping, decreasing fear avoidance, increasing physical loadability, increasing activities and participation (n = 175) (yes/no) | 96 (54.9)/79 (45.1) | 23 (24.5)/71 (75.5) | 73 (90.1)/8 (9.9) | |
| Phase IVa (inestimable recovery): 7–12 weeks: see Phase IIIa + minimizing delay in work participation (n = 8) (yes/no) | 5 (62.5)/3 (37.5) | 1 (33.3)/2 (66.7) | 4 (80.0)/1 (20.0) | |
| Phase IVb (delayed recovery): 7–12 weeks: see Phase IIIb (n = 175) (yes/no) | 124 (70.9)/51 (29.1) | 25 (34.7)/47 (65.3) | 99 (96.1)/4 (3.9) | |
| Phase V (chronic): 3–6 months: see Phase IIIb (n = 155) (yes/no) | 128 (82.6)/27 (17.4) | 16 (48.5)/17 (51.5) | 112 (91.8)/10 (8.2) | |
| Phase VI (chronic): >6 months: see Phase IIIb (n = 121) (yes/no) | 71 (58.7)/50 (41.3) | 22 (33.8)/43 (66.2) | 49 (87.5)/7 (12.5) | |
| Prognostic duration of treatment period | ||||
| <3 months | 64 (7.9) | – | 64 (14.0) | |
| 4–6 months | 230 (28.4) | 129 (36.5) | 101 (22.1) | |
| >6 months | 516 (63.7) | 224 (63.5) | 292 (63.9) | |
| Prognostic number of treatment sessions | ||||
| 1–10 sessions | 78 (9.6) | 13 (3.7) | 65 (14.2) | |
| 11–15 sessions | 253 (31.2) | 143 (40.5) | 110 (24.1) | |
| 16–20 sessions | 313 (38.6) | 197 (55.8) | 116 (25.4) | |
| >20 sessions | 166 (20.5) | – | 166 (36.3) | |
| Pretreatment measures pain (Visual Analog scale [VAS]: 0–100) and functioning (Neck Disability Index [NDI]: 0–50) (since 2002; n = 523) (yes/no) | 495 (94.6)/28 (5.4) | 38 (57.6)/28 (5.4) | 457 (100) – | |
| Treatment plan in agreement with patient (yes) | 810 (100) | 353 (100) | 457 (100) | – |
| Physiotherapy modalities with best available evidence in agreement with treatment goals per phase since accident | ||||
| Phase I: Education, coaching, active exercise therapy (n = 11) (yes/no) | 9 (81.8)/2 (18.2) | 2 (66.7)/1 (33.3) | 7 (87.5)/1 (12.5) | |
| Phase II: See Phase I + cervical soft collar (<1 week), massage therapy (<2 weeks) (n = 82) (yes/no) | 67 (81.7)/15 (18.3) | 14 (60.9)/9 (39.1) | 53 (89.8)/6 (10.2) | |
| Phase IIIa: See Phase I + physical loading exercise therapy (n = 12) (yes/no) | 10 (83.3)/2 (16.7) | 1 (33.3)/2 (66.7) | 9 (100) – | |
| Phase IIIb: Pain education, exercise therapy based on cognitive and physical principles (n = 96) (yes/no) | 80 (83.3)/16 (16.7) | 21 (67.7)/10 (32.3) | 59 (90.8)/6 (9.2) | |
| Phase IVa: See Phase IIIa + graded activity (n = 5) (yes/no) | 3 (60.0)/2 (40.0) | 1 (33.3)/2 (66.7) | 2 (100) | |
| Phase IVb: See Phase IIIb + graded exposure (n = 124) (yes/no) | 107 (86.3)/17 (13.7) | 19 (63.3)/11 (36.7) | 88 (93.6)/6 (6.4) | |
| Phase V: See Phase IVb (n = 128) (yes/no) | 110 (85.9)/18 (14.1) | 14 (58.3)/10 (41.7) | 96 (92.3)/8 (7.7) | |
| Phase VI: See Phase V (n = 71) (yes/no) | 56 (78.9)/15 (21.1) | 8 (53.3)/7 (46.7) | 48 (85.7)/8 (14.3) | |
| Check for treatment side or adverse effects (yes) | 810 (100) | 353 (100) | 457 (100) | – |
| Evaluation during treatment process (yes) | 790 (97.5) | 333 (94.3) | 457 (100) | |
| If necessary, adjustment of treatment goals and modalities (yes) | 185 (22.8) | 38 (10.8) | 147 (32.7) | |
| Contact physician if insufficient treatment result (yes) | 247 (30.5) | 67 (19.0) | 180 (39.4) | |
| Final evaluation (yes) | 810 (100) | 353 (100) | 457 (100) | – |
| Posttreatment measures pain (VAS: 0–100) and functioning (NDI: 0–50) (since 2002; n = 523) (yes/no) | 495 (94.6)/28 (5.4) | 38 (57.6)/28 (42.4) | 457 (100)/- | |
| Evaluation by global perceived effect (GPE 0–7) (since 2002; n = 523) (yes/no) | 495 (94.6)/28 (5.4) | 38 (57.6)/28 (42.4) | 457 (100)/- | |
| Duration of treatment period | ||||
| 2–3 months | 280 (34.6) | 144 (40.8) | 136 (29.8) | |
| 4–6 months | 501 (61.9) | 180 (51.0) | 321 (70.2) | |
| >6 months | 29 (3.6) | 29 (8.2) | – | |
| Number of treatment sessions | ||||
| >5 | 2 (0.2) | 2 (0.6) | – | |
| 5–10 | 10 (1.2) | 7 (2.0) | 3 (0.7) | |
| 11–15 | 329 (40.6) | 184 (52.1) | 145 (31.7) | |
| 16–20 | 405 (50.0) | 160 (45.3) | 245 (53.6) | |
| >20 | 64 (7.9) | – | 64 (14.0) | |
| Reason for discharge (yes) | 810 (100) | 810 (100) | 810 (100) | – |
| Written report (yes) | 810 (100) | 810 (100) | 810 (100) | – |
| Arrangement of aftercare (since 2003; n = 457) (yes) | 151 (33.0) | – | 151 (33.0) | – |
Notes:
P ≤ 0.05;
No statistics: n ≤ 20;/–, no statistics.
Abbreviation: GPE, global perceived effect.
Differences between Group A 1996–2002 (n = 353) and Group B 2003–2011 (n = 457) expressed as percentages of QIs of the clinical reasoning process and performance target for physiotherapy in patients with Whiplash-associated disorders (WAD)
| Steps of clinical peasoning process I–IX indicators | 1996–2002 n = 353 | 2003–2011 n = 457 | Difference | 1996–2002 n = 353 | 2003–2011 n = 457 |
|---|---|---|---|---|---|
| Mean (SD) | Mean (SD) | Significance * | Performance target “+” ≥80% or ≤30% | ||
| Indicator 1: patient’s information (IV) | 80.6 (3.9) | 87.0 (3.3) | * | + | + |
| Indicator 2: patient’s request for help (IV) | 82.3 (1.5) | 87.9 (3.6) | * | + | + |
| Indicator 3: sociodemographic characteristics (IV) | 95.7 (2.8) | 90.4 (3.7) | * | + | + |
| Indicator 4: accident related information (IV) | 79.0 (6.5) | 81.1 (3.8) | + | ||
| Indicator 5: preexistent functioning (IV) | 12.5 (4.5) | 17.6 (4.2) | * | + | + |
| Indicator 6: preexistent health status before injury (IV) | 11.6 (7.3) | 16.7 (4.1) | + | + | |
| Indicator 7: previous diagnostics and treatment (IV) | 56.0 (15.8) | 39.5 (4.2) | * | ||
| Indicator 8: current health status/functioning in ICF terms (IV) | 100 (0.0) | 100 (0.0) | + | + | |
| Indicator 9: recovery since accident and prognostic factors (IV) | 67.4 (8.8) | 73.2 (3.6) | |||
| Indicator 10: objectives of examination (IV) | 58.5 (4.7) | 70.9 (4.8) | * | ||
| Indicator 11: musculoskeletal examination (II–IV) | 100 (0.0) | 100 (0.0) | + | + | |
| Indicator 12: neurological examination (IV) | 76.3 (21.4) | 85.3 (10.6) | + | ||
| Indicator 13: otoneurological examination (since 2000; number of years: n = 12) (IV) | 47.6 (30.4) | 74.7 (11.8) | |||
| Indicator 14: psychological examination: observation (since 2000; number of years: n = 3), questionnaires (since 2003; number of years: n = 9) (II–IV) | 45.4 (11.7) | 99.8 (0.6) | * | + | |
| Indicator 15: analysis and conclusion of diagnostic process (II–IV) | 55.7 (7.3) | 83.3 (2.4) | * | + | |
| Indicator 16: presence of central sensitization (since 2009; number of years: n = 3) (IV) | − | 46.5 (7.5) | Nondefined | ||
| Indicator 17: treatment goals (IV) | 86.8 (5.6) | 90.8 (1.9) | + | + | |
| Indicator 18: prognostics of treatment period and sessions (IV) | 77.5 (7.4) | 76.6 (15.9) | |||
| Indicator 19: pretreatment scores pain (VAS) and functioning (NDI) (since 2003; number of years: n = 9) (I) | − | 100 (0.0) | + | ||
| Indicator 20: (manual) physiotherapy modalities (II–IV) | 65.2 (13.9) | 72.3 (5.0) | |||
| Indicator 21: side effects (IV) | 100 (0.0) | 100 (0.0) | + | + | |
| Indicator 22: evaluation during treatment (IV) Indicator 23: subjective end evaluation treatment goals (IV) | 71.3 (6.9) 91.7 (2.7) | 79.7 (4.3) 90.8 (5.9) | * | + | + |
| Indicator 24: objective end evaluation posttreatment pain (VAS) and functioning (NDI) (2002; number of years: n = 1; since 2003; number of years: n = 9) (I) | 57.6 | 98.7 (3.9) | + | ||
| Indicator 25: global perceived effect (2002; number of years: n = 1; since 2003; number of years: n = 9) (II) | 57.6 | 100 (0.0) | + | ||
| Indicator 26: duration treatment period and number treatment sessions (IV) | 100 (0.0) | 100 (0.0) | + | + | |
| Indicator 27: final report of discharge (IV) | 100 (0.0) | 100 (0.0) | + | + | |
| Indicator 28: after care (since 2003; number of years: n = 9) (IV) | − | 32.4 (11.0) | Nondefined | ||
Notes:
Description of type and number of variables per indicator for analysis: see Supplementary S2;
Full description of indicators: see Supplementary S3;
Levels of evidence: I = systematic review or >2 high-quality controlled trials or high-quality diagnostic studies or high-quality psychometric studies; II = two high-quality controlled trials or high-quality diagnostic studies or high-quality psychometric studies; III = high-quality noncontrolled trials or low-quality diagnostic studies or low-quality psychometric studies; IV = experts opinion and professional consensus or standard.
Abbreviations: NDI, Neck Disability Index; VAS, Visual Analog Scale; QI, quality indicator; ICF, International Classification of Functioning, Disability, and Health.