THE COGNITIVE-BEHAVIOURAL FRAMEWORK IN PAIN PSYCHOLOGY .1  Theory

The  CB  perspective  presented  by  Turk  et  al.  (1983)  is  the  most  widely  accepted  model  in  the   field  of  pain  psychology.  The  CB  approach  to  chronic  pain  is  based  on  several  propositions   (Keefe  et  al.  1992,  Turk  and  Rudy  1992),  the  central  one  being  that  an  individual'ʹs  emotions   and  behavioural  activity  in  response  to  an  event  are  influenced  by  the  cognitive  appraisal   and  interpretation  of  that  event.  The  CB  perspective  on  pain  grew  out  of  developments  in   pain  theory  dating  back  to  Melzack  and  Wall'ʹs  gate  control  theory  (1965).  The  gate  control   theory   has   two   main   principles.   Firstly,   the   gating   mechanism   in   the   dorsal   horn   of   the   spinal  cord  can  control  the  transmission  of  nociceptive  signals  from  a  peripheral  site  to  the   brain.  Secondly,  the  spinal  gating  of  noxious  signals  is  controlled  not  only  by  input  from   the   periphery,   but   also   by   input   from   higher   brain   centres   responsible   for   thoughts,   feelings,   and   behaviours.   The   gate   control   theory   provides   an   explanation   for   why   some   psychological   factors   (e.g.   active   coping,   optimism)   can   reduce   pain   while   others   (e.g.  

anxiety,  depression)  can  increase  pain.    

In  rehabilitation,  CB  approaches  aim  to  improve  the  way  that  individuals  manage  and   cope   with   their   pain.   Rather   than   trying   to   find   a   biological   explanation   for   the   pain   problem,   CB   treatments   focus   on   returning   control   to   the   sufferer.   Patients   with   chronic   pain  are  viewed  as  active  processors  of  information.  They  have  negative  expectations  about   their   own   ability   and   responsibility   to   exert   any   control   over   their   pain.   Moreover,   they   often  view  themselves  as  helpless.  Such  negative,  maladaptive  appraisals  of  their  situation   and  their  personal  efficacy  may  reinforce  the  experience  of  demoralization,  inactivity,  and   overreaction   to   nociceptive   stimulation.   Such   cognitive   appraisals   and   expectations   are   postulated  as  having  an  effect  on  behaviour,  leading  to  reduced  effort  and  activity  as  well   as  increased  psychological  distress  (Turk  and  Rudy  1992).    

CB   treatments   for   pain   commonly   cover   three   main   elements   (Dixon   et   al.   2007).  

Firstly,   they   try   to   provide   an   educational   rationale,   such   as   the   gate   control   theory   (Melzack   and   Wall   1965),   that   helps   the   patients   to   better   understand   the   interrelated   nature  of  their  thoughts,  feelings,  behaviour  and  pain  perceptions.  The  second  element  is   comprised  of  therapist-­‐‑guided  training  in  cognitive  and  behavioural  coping  strategies  such   as   progressive   relaxation   training,   brief   relaxation   methods,   goal   setting,   activity   pacing,   imagery,  and  strategies  for  modifying  overly  negative  thoughts  related  to  pain.  The  final   element  involves  home  practice  of  coping  skills  and  learning  how  to  apply  these  skills  to   pain-­‐‑related  situations  in  daily  life.  With  these  methods,  patients  may  feel  that  they  regain   control  of  their  lives,  and  are  able  to  do  more  and  feel  better.    

2.5.2  Applications  for  knee  osteoarthritis  patients      

The  drawing  of  conclusions  on  psychological  interventions  for  knee  OA  is  difficult  due  to   the   variability   among   previous   studies,   which   have   been   heterogeneous   in   terms   of   the   intervention  (group  or  individual  programmes,  of  different  lengths),  underlying  theory  and   methods.   In   the   recent   Cochrane   review   (Kroon   et   al.   2014)   on   OA   self-­‐‑management   programmes  many  interventions  included  behavioural  and  cognitive  components  as  a  part   of  the  programme  but  other  conservative  treatment  modalities,  such  as  exercise,  were  also   incorporated.   Thus,   the   impact   and   significance   of   the   CB   part   of   the   intervention   is   difficult  to  determine.    

Studies  applying  plain  CB  interventions  for  knee  OA  patients  are  presented  in  Table  4.  

All   in   all,   seven   out   of   eight   studies   have   used   an   intervention   called   pain   coping   skills   training  (PCST),  and  at  least  partly  the  same  researchers  have  been  involved  in  them.  One   of   the   earliest   studies   was   a   three-­‐‑arm   RCT   testing   a   10-­‐‑week   group-­‐‑based   PCST   programme   in   comparison   to   arthritis   educational   (AE)   classes   and   standard   care   (SC)   (Keefe  et  al.  1990a,  Keefe  et  al.  1990b).  In  this  study,  knee  OA  was  diagnosed  on  the  basis  of   medical   evaluation   and   radiographic   examination.   However,   more   detailed   information   was   not   given   on   the   radiographic   findings   or   diagnostic   criteria   used.   The   results   regarding  pain  reduction  were  short-­‐‑lived.  There  were  significant  differences  between  the   PCST  and  AE  groups  in  physical  and  psychological  function  in  favour  of  the  PCST  group.  

Interestingly  however,  these  differences  were  not  present  between  PCST  and  SC  groups.    

Next,   Keefe   et   al.   (1996,   1999)   studied   the   efficacy   of   a   group-­‐‑based   spouse-­‐‑assisted   coping  skills  training  (SA-­‐‑CST)  programme.  Again,  this  was  a  three-­‐‑arm  RCT  with  control   groups   attending   CST   without   spousal   involvement   or   10   group   sessions   with   arthritis   education  with  spousal  support  (AE-­‐‑SS).  The  participants  in  this  study  were  diagnosed  as   having  OA,  but  the  diagnostic  criteria  used  were  not  specified.  At  the  one-­‐‑year  follow-­‐‑up,   self-­‐‑efficacy  and  pain  coping  for  the  SA-­‐‑CST  group  were  significantly  better  in  comparison   to  the  AE-­‐‑SS  group.  Once  again,  the  reduction  in  pain  was  out  washed  during  the  follow-­‐‑

up.   Later   on,   PCST   was   studied   in   a   four-­‐‑arm   RCT   examining   the   effects   of   a   12-­‐‑week   group-­‐‑based   spouse-­‐‑assisted   PCST   (SA-­‐‑PCST)   in   combination   with   exercise   training   (ET)   (Keefe   et   al.   2004).   The   participants   had   been   diagnosed   with   OA   of   the   knees   and   underwent   a   physical   examination   by   a   rheumatologist.   Again,   however,   no   exact   information   was   given   on   the   set   of   diagnostic   criteria   used.   The   combined   intervention   group  (SA-­‐‑PCST  +  ET)  demonstrated  significant  pretest-­‐‑posttest  differences  in  self-­‐‑efficacy   and  pain  coping  in  comparison  to  ET  and  SC  interventions  alone.  No  follow-­‐‑up  data  have   been  published  from  this  study.  

Riddle   et   al.   (2011)   performed   a   quasi-­‐‑experimental   study   among   patients   scheduled   for  primary  knee  arthroplasty  and  with  high  initial  catastrophizing  scores  measured  with   the  PC  scale  (Riddle  et  al.  2010).  The  comparison  was  with  a  historical  cohort  scheduled  for   knee  arthroplasty  and  receiving  usual  care.  The  radiological  severity  of  their  knee  OA  was   not   reported,   but   considering   the   setting,   one   can   assume   that   they   were   mostly   KL3−4.  

Two  months  after  the  surgery,  the  study  demonstrated  significantly  better  improvements  in   pain,   physical   function   and   pain   catastrophizing   for   the   PCST   group   compared   to   a   historical  cohort.  

Somers  et  al.  (2012)  conducted  a  four-­‐‑arm  RCT  with  a  combined  PCST  and  behavioural   weight   management   (BWM)   intervention.   The   PCST   intervention   in   this   study   was   particularly  long  lasting  for  one  year  with  18  group  sessions  and  6  monthly  phone  calls.  

The   participants   had   to   fulfil   the   ACR   clinical   criteria   for   knee   OA   and   have   KL1−4   radiological  knee  OA.  The  results  were  analysed  with  the  mixed  model  and  the  combined   intervention  group  achieved  significantly  better  results  (post-­‐‑treatment  average)  compared   to   all   other   study   groups   for   pain   improvement,   physical   function,   self-­‐‑efficacy   and   catastrophizing.   Comparisons   between   the   single   PCST   intervention   and   SC   were   not   reported.   However,   considering   the   post-­‐‑treatment   average   levels   of   different   pain   and   function  measures,  there  were  probably  no  significant  differences.    

Recent   studies   using   PCST   as   an   intervention   have   addressed   questions   of   its   accessibility.   Firstly,   the   effectiveness   of   an   individual   PCST   programme   held   by   trained   primary  care  nurse  practitioners  was  tested  (Broderick  et  al.  2014).  The  participants  had  to   have   knee   or   hip   OA   confirmed   by   their   physician.   Radiographs   were   evaluated   at   baseline,   but   even   KL0   was   accepted.   Follow-­‐‑up   results   revealed   significantly   better   outcomes  for  the  PCST  group  in  pain  reduction,  physical  function,  psychological  function,   pain   coping   and   catastrophizing.   In   this   study,   particular   emphasis   was   placed   on   educating  and  reaffirming  the  adherence  of  the  nurse  practitioners  to  the  programme.  The   most  recent  study  by  Rini  et  al.  (2015)  was  an  RCT  pilot  for  testing  the  effectiveness  of  an  

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eight-­‐‑week  Internet-­‐‑based  PCST  programme  in  patients  with  ≥KL2  knee  or  hip  OA.  Initial   improvements   in   pain   reduction   for   women   and   self-­‐‑efficacy   for   the   intervention   group   were  reported,  but  since  the  study  was  a  pilot,  it  did  not  have  sufficient  statistical  power  for   any  further  conclusions.  Finally,  both  of  these  studies  included  patients  with  hip  or  knee   OA,   and   thus   the   effect   of   the   intervention   on   knee   OA   patients   is   difficult   to   decipher,   since  they  were  not  analysed  separately.  

The   remaining   study   testing   a   group-­‐‑based   CB   intervention   on   OA   patients   was   conducted   in   the   early   1990s   by   Calfas   et   al.   (1992).   In   this   two-­‐‑arm   RCT,   patients   could   have   OA   of   any   joint,   and   the   number   of   patients   with   knee   OA   in   the   study   was   not   reported.  At  the  2-­‐‑month  follow-­‐‑up  point,  a  significant  difference  was  detected  between  the   study  groups,  but  the  effect  was  washed  out  by  the  12-­‐‑month  follow-­‐‑up  point.    

In   summary,   studies   have   demonstrated   that   a   plain   CB   intervention   has   at   most   a   short-­‐‑term  impact  on  pain  and  function  in  the  conservative  treatment  of  knee  OA  patients.  

Heterogeneity   remains   in   the   results   concerning   psychological   function,   self-­‐‑efficacy   and   pain   coping.   From   the   point   of   view   of   knee   OA   patients,   limitations   in   these   studies   include  the  lack  of  radiological  verification  of  OA  or  its  vagueness,  and  their  inclusion  of   other  OA  joint  groups.  

Table 4.

Studies with plain cognitive-behavioural interventions for knee OA patients. Research group, study type, country

Sample size No. of groups Inclusion criteriaInterventionControl Outcome assessment Outcome measures 1) Pain reduction 2) Physical function 3) Psychological function 4) Self-efficacy 5) Pain coping 6) Catastrophizing

Results 1) Pain reduction 2) Physical function 3) Psychological function 4) Self-efficacy 5) Pain coping 6) Catastrophizing Keefe et al. (1990a, 1990b), randomized controlled trial, USA

99, mean age 64 years

3 1) Knee OA diagnosed by medical evaluation and radiographic examination; 2) no other form of arthritis or organic disease significantly affecting function; 3) not receiving disability support payments for OA.

Treatment period: 10 weekly group sessions of PCST (n=32); follow-up (6 months): phone calls at 1, 2 and 4 months 1) 10 weekly AE sessions (n=36); phone calls at 1, 2 and 4 months during the follow-up 2) SC (n=31) Pretest- posttest; follow-up (6 months)

1) AIMS 2) AIMS 3) AIMS 4) NA 5) CSQ 6) NA

Posttest: 1) PCST > AE and SC 2) NS 3) PCST > AE and SC AE > SC 4) NA 5) NR 6) NA Follow-up: 1) NS 2) PCST > AE PCST vs. SC -> NS 3) PCST > AE PCST vs. SC -> NS 4) NA 5) NR 6) NA Calfas et al. (1992), randomized controlled trial (pilot study, not statistically sufficient power), USA

40, mean age 67 years

2 1) Adult; 2) OA (any joint) diagnosed by a physician according to the American Rheumatology Association criteria; 3) at least “modest” functional impairment in one or more functional questions.

10 weekly group sessions of CB modification AE (series of didactic lectures) Pretest- posttest; follow-up (2, 6 and 12 months) 1) AIMS 2) AIMS 3) AIMS, BDI 4) NA 5) NA 6) NA

Follow-up 2 months: 1) NS 2) CB > AE 3) CB > AE (BDI) 4) NA 5) NA 6) NA Follow-up 12 months: 1) NS 2) NS 3) CB > AE (BDI) 4) NA 5) NA 6) NA

Keefe et al. (1996, 1999), randomized controlled trial, USA

88, mean age 63 years

3 1) Married; 2) diagnosed as having OA of the knees; 3) not having any other arthritic disorders other than OA; 3) no other known organic disease that would significantly affect function; 4) not receiving disability payments for OA.

10 weekly group sessions of SA-CST held by a psychologist and a nurse 1) CST without spousal involvement 2) 10 weekly group sessions of AE-SS Pretest- posttest; follow-up (6 and 12 months)

1) AIMS 2) AIMS 3) AIMS 4) ASES 5) CSQ (factors: Coping Attempts, Pain Control and Rational Thinking) 6) NA

Posttest: 1) SA-CST > AE-SS 2) NS 3) SA-CST > AE-SS 4) SA-CST and CST > AE-SS 5) SA-CST > AE-SS 6) NA Follow-up 12 months: 1) NS 2) CST > AE-SS SA-CST vs. AE-SS -> NS 3) NS 4) SA-CST > AE-SS 5) SA-CST > AE-SS 6) NA Keefe et al. (2004), randomized controlled trial, USA

72, mean age 60 years

4 1) Diagnosed as having knee OA; 2) persistent pain due to knee OA; 3) having a spouse.

12 weekly group sessions of SA-PCST + 12 weekly sessions of ET 1) SA-PCST 2) PCST alone 3) ET alone 4) SC Pretest- posttest (week 12) 1) AIMS 2) AIMS 3) AIMS 4) ASES 5) CSQ 6) NA

Posttest: 1) NS 2) NS 3) NS 4) SA-PCST + ET > ET and SC SA-PCT alone > SC 5) SA-PCST + ET > ET and SC SA-PCT alone > ET and SC 6) NA

Riddle et al. (2011), quasi- experimen- tal study, USA

63, mean age 62 years

2 1) Patients scheduled for primary unilateral knee arthroplasty; 2) scored ≥16 on the PC Scale; 3) able to speak and read English.

8 sessions of PCST (n=18) held by a psychologist: one individual session a month prior and a month following the surgery, 6 telephone- based sessions between them HC (n=45) Baseline; follow-up (2 months after surgery)

1) WOMAC 2) WOMAC 3) NA 4) NA 5) NA 6) PC Scale

Follow-up: 1) PCST > HC 2) PCST > HC 3) NA 4) NA 5) NA 6) PCST > HC Somers et al. (2012), randomized controlled trial, USA

232, mean age 58 years

4 1) Knee pain on most days of the month for at least 6 months; 2) ≥18 years old; 3) BMI ≥25 and ≤42; 4) met the ACR clinical criteria for OA and had radiological evidence (KL 1-4) of knee OA; 5) no other weight- bearing joint affected by OA; 6) knee OA was the primary contributor to the daily function; 7) able to read and speak English.

Treatment period: 18 (12 weekly, 6 every other week) group sessions of PCST and BWM (n=62); follow-up period: 6 monthly phone calls 1) PCT alone (n=60) 2) BWM alone (n=59) 3) SC (n=51)

Pretest- posttest (6 months); follow-up (6 and 12 months) 1) AIMS, WOMAC 2) AIMS, WOMAC 3) AIMS 4) ASES 5) NA 6) CSQ catastrophizing subscale

Baseline – posttreatment average: 1) PCTS + BWM > all other study groups (AIMS, WOMAC) 2) PCTS + BWM > all other study groups (AIMS, WOMAC) 3) NS 4) PCTS + BWM > all other study groups 5) NA 6) PCTS + BWM > all other study groups

Broderick et al. (2014), randomized controlled trial, USA

257, mean age 67 years, knee OA in 77% (n=199)

2 1) Physician- confirmed diagnosis of hip or knee OA (KL 0-4); 2) ≥21 years old; 3) usual pain ≥4 on a 10-point scale of at least 6 months; 4) ability to read, write, understand English; 5) ability to attend 10 intervention sessions; 6) no cognitive/mental impairment; 7) no expected joint replacement surgery.

10 individual weekly sessions of PCST (n=129) held by nurse practitioners SC (n=127) Pretest- posttest; follow-up (6 and 12 months)

1) Composite measure of AIMS, Brief Pain Inventory, WOMAC 2) Composite measure of AIMS, WOMAC 3) Composite measure of AIMS, BDI 4) ASES 5) CSQ subscales excluding the catastrophizing subscale 6) CSQ catastrophizing subscale

Pretest-posttest: 1) PCTS > SC 2) PCTS > SC 3) PCTS > SC 4) PCTS > SC 5) PCTS > SC 6) NS Follow-up 12 months: 1) PCTS > SC 2) PCTS > SC 3) PCTS > SC 4) NS 5) PCTS > SC 6) PCTS > SC Rini et al. (2015), randomized controlled trial (pilot study, not statistically sufficient power), USA

113, mean age 67 years, knee OA 35% (n=40), knee and hip OA 52% (n=59)

2 1) ≥18 years old; 2) with hip or knee OA, confirmed radiographically (KL≥2, with associated pain), with ACR clinical criteria, or by their physician; 3) able to speak English; 4) OA related pain on most days of the month for 3 months.

8-week (8- module) Internet- based PCST programme (n=58) SC (n=55) Pretest- midpoint (5 weeks)- posttest

1) AIMS2 2) AIMS2 3) Pain Anxiety Symptoms Scale, Positive and Negative Affect Scale 4) ASES 5) NA 6) NA

Pretest-posttest: 1) PCST > SC for women 2) NS 3) NS 4) PCST > SC 5) NA 6) NA PCST, pain coping skills training; AE, arthritis education; SC, standard care; AIMS/AIMS2, Arthritis Impact Measurement Scale; NA, not assessed; CSQ, coping skills questionnaire; NS, non-significant; NR, not recorded; CB, cognitive-behavioural; BDI, Beck’s Depression Inventory; SA-CST/-PCST, spouse- assisted coping/pain coping skills training; AE-SS, arthritis education with spousal support; ASES, Arthritis Self-Efficacy Scale; CSQ, Coping Strategies Questionnaire; PC Scale, Pain Catastrophizing Scale; ET, exercise training; HC, historical cohort; BMI, body mass index; BWM, behavioural weight management; ACR, American College of Rheumatology; KL, Kellgren–Lawrence grade.