Original Articles
 

By Dr. Deepak Gupta , Ms. Alyssa Drabik , Dr. Shushovan Chakrabortty
Corresponding Author Dr. Deepak Gupta
Wayne State University, - United States of America 48201
Submitting Author Dr. Deepak Gupta
Other Authors Ms. Alyssa Drabik
Anesthesiology, Detroit Medical Center, - United States of America

Dr. Shushovan Chakrabortty
Anesthesiology, Wayne State University, - United States of America

PAIN

Nominal Scale, Yes-No-Don't Know-YNDK Scale, Ordinal Scale, Numerical Rating Scale-NRS, Pain Clinic, Chronic Pain

Gupta D, Drabik A, Chakrabortty S. A New Nominal Scale (Yes-No-Don't Know-YNDK Scale) and Its Correlation with Standard Ordinal Scale (Numerical Rating Scale-NRS): Our Experience Among University Based Pain Clinic Patients. WebmedCentral PAIN 2016;7(11):WMC005226

This is an open-access article distributed under the terms of the Creative Commons Attribution License(CC-BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
No
Submitted on: 15 Nov 2016 04:22:43 AM GMT
Published on: 15 Nov 2016 06:42:09 AM GMT

Abstract


Background: There are variety of pain scales available for use by the health care providers to assess patients' pain. Numerical rating scales (11-point 0-10 NRS) are one of the most commonly used pain scales for pain assessment, although some studies have questioned the adequacy of NRS for pain assessment.

Objectives: To assess how well the standard ordinal scale (11-point NRS) correlates with a simplified nominal scale (3-point expectation score), named by us as Yes-No-Don't Know (YNDK) scale when used in chronic pain patients presenting to our University Based Pain Clinic.

Methods: During the study period, patients in our pain clinic were assessed for pain severity score per NRS, pain relief score per NRS, satisfaction with current pain medication regimen per YNDK scale, expectation of change in current pain medication regimen per YNDK scale, and whether that expectation was eventually met at our pain clinic.

Results: A total of 243 patients were included in our study. It was worth noting that included patients were primarily middle aged (67%); new patients were primarily males (82%), while follow-up patients were primarily females (62%). There was strong correlation (positive or inverse) amongst majority of correlated NRS scores and YNDK scale scoring.  Despite more than 3/4th of patients reporting severe pain (NRS 7-10), only less than half of these patients wanted their pain medications changed per YNDK scale.

Conclusions: Despite simplifying the pain assessment, 3-point YNDK score may be an appropriate adjunct for pain scoring wherein it can be used independently, complementarily or supplementary to 11-point NRS score in rapid turnover pain clinics to improve fulfillment of chronic pain patients' expectations.

Introduction


There are variety of pain scales available for use by the health care providers to assess patients' pain1 and due to their ease of use in clinical practice, numerical rating scales (11-point 0-10 NRS)2 are one of the most commonly used pain scales for pain assessment. Use of NRS for pain assessment has been validated in multiple studies although some studies have questioned the adequacy of NRS for pain assessment1-6. On one end of the spectrum, NRS may interfere in comprehensive assessment of chronic pain because other pain and symptom descriptors are missing in these simplified NRS scores7. On the other end of the spectrum, it is an unsubstantiated yet common belief that many patients presenting to pain clinics solely expect quick-fixes for their chronic pain, primarily with pain medications. At this end of the spectrum lies an opportunity to simplify 11-point NRS further as the other end of the spectrum needs exhaustive list-based complex pain assessment tools that have always been available but are too difficult to use in current day rapid turnover busy pain clinics. Additionally, when patients rate their pain chronically as 4-6 on 0-10 NRS, it is sometimes not clear whether patients are satisfied with their pain control regimen. However, when patients rate their pain chronically as 7-10 on 0-10 NRS and yet do not request/agree with need for change in pain control regimen, physicians often find it difficult whether their patients are appropriately rating their pain when using 0-10 NRS especially for chronic pain. Therefore, it is worthwhile to assess how well the standard ordinal scale (11-point NRS) correlates with a simplified nominal scale (3-point expectation score), named by us as Yes-No-Don't Know (YNDK) scale.

The objective of our study was to ascertain whether scores on 3-point YNDK scale correlate adequately with 11-point NRS scores when used in chronic pain patients presenting to our University Based Pain Clinic.

Materials and Methods


Our institutional review board determined the project as non-human participant research according to the coded definitions in the Common Rule under Code of Federal Regulations Title 45 Part 46 (45 CFR 46) per Food and Drug Administration (FDA) regulations. Subsequently, during the brief study period spanning over one month, patients in our pain clinic were assessed for following: (a) age, (b) sex, (c) type of visit (first time visit or follow-up visit) to pain clinic, (d) pain severity score per NRS wherein from 0 to 10 graded as progressively increasing severity of pain, (e) pain relief score per NRS wherein from 0 to 10 graded as progressively improving pain relief with medications, (f) satisfaction with current pain medication regimen per YNDK scale, (g) expectation of change in current pain medication regimen per YNDK scale, and (h) whether that expectation was eventually met at our pain clinic (Figure 1) by the prescribing physicians who were blinded to YNDK scale scores of their patients.

The limited datasets were tabulated and the only comparisons performed were correlations via regression analysis while designating p value of < 0.05 as significant value.

Results


A total of 243 patients were included in our study and their results have been tabulated in Tables 1-2.  It was worth noting that included patients were primarily middle aged, 45-65 years of age (67%). During our brief study period, patients presenting to our clinic for first time were primarily males (82%), while patients following up with our clinic were primarily females (62%). It can be safely said that the patients had easily understood the pain scoring by NRS as well as by YNDK scale because only less than 1/4th among any of the grouped patients (Table 1) responded as DON'T KNOW (NOT SURE) for what the scoring expectations and/or their own expectations were in regards to pain management at our clinic. There was strong correlation (positive or inverse) amongst majority of correlated NRS scores and YNDK scale scoring (Table 2 and Figure 2).  On reformatting the distribution of NRS and YNDK scale based responses by the patients into a 3x3 contingency table (Table 3), it became clear that despite more than 3/4th of patients reporting severe pain (NRS 7-10), only less than half of these patients wanted their pain medications changed.

Discussion


Although the patients, who presented for the first time to our pain clinic, were excluded from the correlation statistics due to very small number (n=17), it can be summarized as following: (a) all patients reported NRS for pain severity at 8 (median and mode) irrespective of their type of visit (first time visit or follow-up visit) to our pain clinic; (b) however, the new patients' scores for NRS pain relief were much lower than the follow-up patients' scores; and (c) as compared to the follow-up patients, higher percentages of the new patients convincingly reported (per YNDK scale) that their pain medications were not working hence requiring medication changes that were more likely fulfilled at our pain clinic eventually. All this could reflect why the new patients had sought the pain clinic services in the first place: for the relief of their intractable pain, definitively non-responsive to their current pain management prior to their first time visit to our pain clinic.

When correlation coefficients were deduced among the follow-up patients who were separated per their gender for statistical analysis purposes, it can be summarized as following: (a) NRS scores and age of the patient did not correlate; (b) as expected, NRS pain severity and NRS pain relief significantly correlated inversely although coefficients were not close to (-)1 as one would expect; (c) surprisingly, NRS pain severity did not translate into significant concordance for increased request for changes in their medication per YNDK; (d) however, NRS pain relief and YNDK score for perception of medications working were strongly concordant and positively correlated; (e) YNDK scores for perception of medications working and need for change in medications did NOT turn up correlation coefficients equal to (-)1 because unsure patients who verbalized/responded "DON'T KNOW" skewed up the coefficients to be lower than (-)1 although yet strongly significant and inversely correlated; and (f) finally, female patients on their follow-up visits were significantly more likely to get their wishes fulfilled in regards to verbalized/voiced needs for changes in medications. Henceforth, it would seem appropriate to draw the following inferences: (a) despite NRS pain severity scores being very high, chronic pain patients might not always report very low NRS pain relief scores correspondingly, assumingly due to their acceptance of guarded expectations in terms of relief from chronic pain; (b) concurrently, chronic pain patients do not always request for changes in their pain medications despite high NRS pain severity scores, assumingly due to their apprehensions against changing their current, imperfect yet somewhat effective pain management regimen; (c) however, reassuringly, chronic pain patients perceptions of medications working and good pain relief reinstated the significant role accrued by the chronic pain patients to the pain medications effectiveness for their pain relief; and (d) lastly, it was ironic that female chronic pain patients were more convincing while conveying their request for change in medications compared to male chronic pain patients exposing the unintentional gender bias during chronic pain management.

Our study has few limitations: The limited data of our local pain clinic's practices and resultant adequacy of the actual pain management was evaluated for our pain clinic's and catered pain patients' self evaluation and reflection; however, our local experience would require validation projects and larger studies in other pain clinics and management institutes. Moreover, the future studies would need to explore whether simplifying pain assessment further via 3-point YNDK scale is warranted either for the ease of the evaluators/assessors or for the ease of documenting chronology of patients' pain management's progress or for the sake of both.

Conclusion


Despite simplifying the pain assessment, 3-point YNDK score may be an appropriate adjunct for pain scoring wherein it can be used independently, complementarily or supplementary to 11-point NRS score in rapid turnover pain clinics to improve fulfillment of chronic pain patients' expectations.

References


  1. HAWKER GA, MIAN S, KENDZERSKA T, FRENCH M: Measures of adult pain: Visual Analog Scale for Pain (VAS Pain), Numeric Rating Scale for Pain (NRS Pain), McGill Pain Questionnaire (MPQ), Short-Form McGill Pain Questionnaire (SF-MPQ), Chronic Pain Grade Scale (CPGS), Short Form-36 Bodily Pain Scale (SF-36 BPS), and Measure of Intermittent and Constant Osteoarthritis Pain (ICOAP). Arthritis Care Res (Hoboken); 2011, 63:S240-252.
  2. MCCAFFERY M, PASERO C: Chapter 3: Assessment; In: Pain: Clinical Manual 2nd Edition; Mosby, Inc. (imprint) Elsevier, Maryland Heights, Missouri, United States 1999.
  3. BOONSTRA AM, SCHIPHORST PREUPER HR, RENEMAN MF, POSTHUMUS JB, STEWART RE: Reliability and validity of the visual analogue scale for disability in patients with chronic musculoskeletal pain. Int J Rehabil Res; 2008, 31:165-169.
  4. KIM EJ, BUSCHMANN MT: Reliability and validity of the Faces Pain Scale with older adults. Int J Nurs Stud; 2006, 43:447-456.
  5. DE C WILLIAMS AC, DAVIES HT, CHADURY Y: Simple pain rating scales hide complex idiosyncratic meanings. Pain; 2000, 85:457-463.
  6. FERRAZ MB, QUARESMA MR, AQUINO LR, ATRA E, TUGWELL P, GOLDSMITH CH: Reliability of pain scales in the assessment of literate and illiterate patients with rheumatoid arthritis. J Rheumatol; 1990, 17:1022-1024.
  7. DANNEMILLER EDUCATION CENTER: A review of the evaluation of pain using a variety of pain scales.  http://cme.dannemiller.com/ar ticles/activity.cfm?id=318&f=1 Last updated on January 31, 2013; Last accessed on May 04, 2016.

Source(s) of Funding


Not Applicable

Competing Interests


Not Applicable

Reviews
0 reviews posted so far

Comments
0 comments posted so far

Please use this functionality to flag objectionable, inappropriate, inaccurate, and offensive content to WebmedCentral Team and the authors.

 

Author Comments
0 comments posted so far

 

What is article Popularity?

Article popularity is calculated by considering the scores: age of the article
Popularity = (P - 1) / (T + 2)^1.5
Where
P : points is the sum of individual scores, which includes article Views, Downloads, Reviews, Comments and their weightage

Scores   Weightage
Views Points X 1
Download Points X 2
Comment Points X 5
Review Points X 10
Points= sum(Views Points + Download Points + Comment Points + Review Points)
T : time since submission in hours.
P is subtracted by 1 to negate submitter's vote.
Age factor is (time since submission in hours plus two) to the power of 1.5.factor.

How Article Quality Works?

For each article Authors/Readers, Reviewers and WMC Editors can review/rate the articles. These ratings are used to determine Feedback Scores.

In most cases, article receive ratings in the range of 0 to 10. We calculate average of all the ratings and consider it as article quality.

Quality=Average(Authors/Readers Ratings + Reviewers Ratings + WMC Editor Ratings)