Influence of Acuity on Physical Therapy Outcomes for Patients With Cervical Disorders

Article Outline

• Abstract
• Methods
  • Study Populations
    • Participants
  • Physical Therapists
  • Interventions
  • Outcome Measure
  • Data Analysis
• Results
• Discussion
  • Study Limitations
• Conclusions
• References
• Copyright

Abstract 

Boissonnault WG, Badke MB. Influence of acuity on physical therapy outcomes for patients with cervical disorders.

Objectives

To assess the influence of symptom acuity on functional outcomes, pain, and patient perception of recovery after a physical therapy (PT) program for cervical disorders and to determine what variables are associated with patient function at discharge.

Design

Retrospective case series.

Setting

Outpatient settings at a tertiary care facility.

Participants

Patients (N=220) who were seen for PT between June 2003 and November 2005.

Interventions

A customized rehabilitation program was developed for each patient based on examination findings and included a combination of the following interventions: mobilization or manipulation, flexibility exercises, strengthening exercises, endurance exercises, massage techniques, and heat and cold modalities.

Main Outcome Measures

Functional outcome, functional improvement, perceived pain, and perceived improvement scores in the CareConnections Outcomes System (formerly TAOS) database.

Results

Persons whose symptom duration was greater than 6 months (chronic group) had significantly less functional improvement than persons whose symptom duration was less than 1 month (acute group). The median percentage improvement score for patient perceived recovery was also significantly lower for the chronic group than for the acute group. There was no significant difference in the percentage decrease in pain among the acute, subacute (symptom duration, 1−6mo), and chronic groups. In regression analyses, a model with age (P=.001), symptom duration (P=.05), and inclusion of mobilization and manipulation interventions (P=.02) fit the data well and explained 35.6% of the variance in functional outcome score for all 3 groups combined.

Conclusions

Patients showed improvements in function after a rehabilitation program for cervical disorders. Patient functional score at discharge is influenced by age, symptom duration, and inclusion of mobilization or manipulation treatments.

Key Words: Mobilization, Prognosis, Rehabilitation, Therapy, manipulation, Treatment outcomes

THE LIFETIME PREVALENCE of cervical disorders appears to almost equal that of low back pain (LBP) episodes with estimates of up to two thirds of the population experiencing this condition.¹, ² With approximately 10% to 25% of people reporting symptoms associated with cervical disorders at any one time and a third reporting moderate to severe pain up to 10 years after the initial episode, the cost in dollars spent on treatment, lost wages, and compensation is significant. Neck disorders cause significant disability in up to 5% of the population with women more adversely impacted than men.¹, ², ³, ⁴, ⁵ Not surprisingly a significant proportion of the population seeking care from physicians, physical therapists, and chiropractors for orthopedic conditions includes patients experiencing these disorders.⁶, ⁷, ⁸, ⁹, ¹⁰ For example, neck pain fell within the top 20 reasons for patient visits to family physicians in 2002 in those aged 44 years and younger.⁶ In addition, patients with cervical disorders constitute the second largest physical therapy (PT) outpatient population, second only to those with LBP; accounting for up to 15% to 20% of the therapy episodes of care.⁷, ⁸, ⁹

Considering the numbers of patients seeking care for cervical disorders, surprisingly few studies have described the interventions used by physical therapists for patients with cervical disorders. Jette and Jette¹¹ reported that heat modalities (91%), flexibility exercises (81%), massage techniques (65%), mobilization or manipulation (interchangeable terms used to describe a manual therapy technique to the joints, including thrust and nonthrust therapeutic maneuvers)¹² (61%), and strengthening exercises (60%) were the most frequently used interventions for patients with cervical impairments. Jette and Delitto,¹³ although reporting similar frequencies for choices of individual interventions across the different stages of care (acute, subacute, or chronic) noted that multimodal therapy (various exercise combinations including aquatic, body mechanics, pain modulation, functional training, postural, proprioceptive, closed-chain, and plyometric exercises) was implemented in a majority of cases. A different pattern of intervention use was noted by Klaber Moffett et al¹⁴ who described “usual treatment” for patients with neck pain provided by physiotherapists in the United Kingdom. Patient education for posture, lifting, and lifestyle was used most frequently (38%) followed by mobilization or manual therapy (25.5%), home exercises (not specified) (21%), and electrotherapy (8%). These studies illustrate a lack of uniformity in treatment approaches for this patient population, including use of individual interventions and varied combinations of treatments.

The goal of rehabilitation management of patients with orthopedic conditions has evolved from a primary goal of pain relief, to minimizing symptoms combined with restoration of function. In addition, assessing change in level of disability is a relatively recent priority in determining patient outcome after PT care. Investigating the attainment of these goals in therapy programs for patients with cervical disorders and factors that impact intervention outcomes is important, especially as an aid to establishing patients’ prognoses and promoting appropriate use of PT resources.

Few studies of patients with cervical conditions have investigated the impact of specific or combinations of PT interventions on level of patient disability and the factors that may influence outcome to such care. Jette and Jette¹¹ reported improved physical and emotional health per the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) in patients with cervical impairments after PT interventions. Improvement was noted in all SF-36 domains except general health perceptions, with the most notable changes occurring in the physical dimension of health. The inclusion of endurance exercises was associated with improved outcomes most frequently in scales measuring the physical and emotional aspects of health. In addition, improved outcome in physical functioning was noted with the inclusion of flexibility exercises, and also in the Neck Disability Index (NDI) with inclusion of strengthening exercises. Last, treatment programs including mobilization or manipulation were associated with better outcomes both in the general health perceptions and in the NDI. Although providing information not previously reported, these authors recommended future studies investigating the relationship of PT intervention programs to health-related outcomes.¹¹ Wang et al¹⁵ reported improvement in disability scores (Patient Specific Functional Scale) in patients with cervical disorders receiving an individualized treatment approach versus a control group. The individualized approach was based on classification of patients into 4 treatment groups. The treatment approach included a broad range of different exercises (eg, postural, range of motion [ROM], stretching, stabilization) and manual therapy interventions. Due to the overall lack of studies, these authors also noted the need for further research describing current treatment approaches for patients with cervical conditions and investigating which patient and clinical factors may influence impact of the interventions on patient disability.¹⁵ Last, whereas Gross et al¹⁶ cited studies supporting the use of mobilization or manipulation, plus exercise for patients with subacute or chronic neck pain, others¹⁷, ¹⁸ reported no or insignificant differences in various outcome indices in patients with chronic neck pain receiving these interventions. In summary, a review of the literature reveals an overall lack of studies investigating the influence of selected rehabilitation interventions and patient characteristics on levels of disability in this large outpatient population, and when findings are compared from many of these studies, conflicting results are noted.

The purposes of this study were: (1) to describe physical therapist intervention choices for patients with cervical disorders, (2) to investigate the impact of the timing of PT intervention on functional outcomes in patients with cervical disorders, and (3) to determine which patient characteristics and choice of intervention variables were associated with patient function at discharge. Identifying factors associated with enhanced or reduced recovery from cervical disorder episodes will assist clinicians in establishing a more accurate prognosis.

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Methods 

Study Populations 

A retrospective medical record review identified 224 patients seen consecutively for treatment of cervical impairments between June 2003 and November 2005 at 1 of 4 University of Wisconsin Hospital/Clinics Orthopedic Outpatient sites. Subjects were searched by International Classification of Diseases−9¹⁹ code of 723.1 or 723.4 as a primary or secondary diagnosis. Patients were excluded if they had previous surgery or were receiving concurrent treatment or procedures for their cervical disorder. Ethics approval was not required because this research was determined to be exempt under 45 Code of Federal Regulations 46.101(b)(4), research involving collection of existing, unidentifiable information.

Subjects were divided into 3 groups based on their symptom duration. For the purpose of this study, per the parameters set by Ross,²⁰ those beginning therapy within 1 month postonset of their symptoms were defined as the acute group, those beginning therapy between 1 month and 6 months postonset were defined as the subacute group, and those beginning therapy more than 6 months postonset were defined as the chronic group.

The CareConnections Outcomes System (formerly TAOS) database contained information from patients who filled out the requisite initial and discharge questionnaires and had a completed episode of care. Four subjects with missing or incomplete data relating to the clinical or outcome variables were excluded from the study analyses. Four of the patients were receiving worker’s compensation for their cervical condition.

Physical Therapists 

A total of 17 physical therapists working in the 4 clinic sites provided the patient care. Fifty-nine percent of the physical therapists were women. The highest credential of 8 of the physical therapists was a bachelor’s degree. Two therapists had an entry-level master’s degree, 6 had an advanced-level master’s degree, and 1 therapist had a doctorate in science. Three physical therapists were board certified in orthopedics by the American Physical Therapy Association (APTA) and 3 were graduates of an APTA-credentialed orthopedic clinical residency program. The average years of clinical practice ± standard deviation (SD) was 15.8±8.4 (range, 2−32). Fifty-eight percent worked full-time treating an average of 40 patients a week.

Interventions 

Table 1 shows the percentages of patients receiving various PT interventions over the treatment duration. Ninety-five percent of the episodes included various combinations of these treatments. The most frequent combinations were flexibility and strengthening exercises (64%), strengthening and mobilization or manipulation (58%), and flexibility, strengthening, and mobilization or manipulation (48%). The number of patient visits ranged from 6 to 8 for each group, over a mean duration of 8.9 weeks for the acute group, 10.5 weeks for the subacute group, and 12.2 weeks for the chronic group.

Table 1. Characteristics of Treatment Program,^⁎ Use of Interventions, and Intensity and Duration of Care for Patients With Cervical Impairments

Characteristics	Acute (n=51)	Subacute (n=115)	Chronic (n=54)
Strengthening exercises	86	78	87
Flexibility exercises	84	76	83
Manipulation or mobilization	63	77	81
Massage techniques	31	44	42
Heat modalities	4	17	11
Endurance exercises	6	6	11
Cold modalities	2	3	2
No. of visits
Mean ± SD	6.2±3.6	7.3±4.9	7.4±4.4
Range	3–23	2–33	3–28
Treatment duration (wk)
Mean ± SD	8.9±6.7	10.5±7.2	12.2±8.6
Range	2–37	1–38	2–40

NOTE: Values are percentages or as otherwise indicated.

Outcome Measure 

The CareConnections Outcomes System was developed by Schunk and Rutt²¹ to evaluate outcomes in orthopedic outpatient rehabilitation patients. The index is a self-report questionnaire designed to address activities specific to 5 anatomic areas: lumbar, lower extremity, upper extremity, cervical, and tempomandibular joint. In addition, each patient reports level of function associated with 5 common activities: walking, work, personal care, sleeping, and recreation and sports. Within each section, there are 6 statements that are scored on a 0 to 5 scale from least functional to most functional. The scores for each question are added together and divided by the total number of points possible for a final score. For our purposes, the cervical portions of the CareConnections were used, which included part I and part II, groups C and D. The CareConnections outcomes tool has been previously found to be a reliable measure of function in patients with musculoskeletal problems.²¹

Further information about the CareConnections outcomes tool and its use has been previously described.²²

The CareConnections patient worksheet was administered during the initial PT visit, and again at discharge. Functional indices, perceived pain, and perceived improvement were scored by an office worker and transferred to software along with the acuity and therapy use information. Functional improvement was defined as the difference between the functional score at the initial visit and the functional score at discharge. Functional outcome was defined as the functional score at discharge. Perceived pain (noted at the initial and final visits) and perceived improvement (noted at the final visit) were measured with a ruler on a visual analog scale (VAS). The pain index ranged from no pain to the worst pain imaginable in the last 24 hours. The improvement index ranged between no improvement and complete recovery since the beginning of therapy treatment. The raw score is the number on the ruler in cm, which corresponded to the patient’s mark. These scores were converted into percentages with the following formulas: (1) percentage decrease in pain = (initial pain − final pain)/initial pain, and (2) percentage improvement = perceived improvement × 10. The repeatability of the VAS is good as noted by correlation coefficients ranging from .97 to .99.²³, ²⁴ Other data available in the CareConnections database included acuity, the number of therapy visits, and treatment duration.

Data Analysis 

We calculated descriptive statistics for the functional outcome, functional improvement, and pain and perceived improvement scores for the 3 groups. Pretherapy to post-therapy differences were compared within groups using a Wilcoxon signed-rank test and between the groups using a Kruskal-Wallis 1-way analysis of variance (ANOVA) by ranks. All 3 symptom duration groups were combined for linear regression analyses, which were used to determine whether any of the treatment characteristics or patient variables was predictive of functional outcome. The major independent variables of interest consisted of age, sex, depression, number of comorbidities, and treatment characteristics (Table 1, Table 2). A univariate analysis was conducted first to determine the relationship between functional outcome and the independent variables. All independent variables that were found to have a significant correlation with the dependent variable were entered into a stepwise regression analysis. This is an interactive process similar to that used by Jette and Jette¹¹ that begins with a regression model containing all independent variables. Subsequent steps involve decisions to retain or delete variables based on their level of association with the dependent variable, their contribution to the model and comparison of the partial F statistic. This process allows variation in the dependent variable to be attributed to a combination of independent variables, both continuous and categorical, and allows control for the baseline value of the dependent variable in a pre and post measurement design. An α level of .01 was used to determine the patient and treatment variables to remain in a model controlled for initial function. All analyses were performed using SAS statistical software.^a

Table 2. Patient Characteristics

Characteristics	Acute (n=51)	Subacute (n=115)	Chronic (n=54)
Age (y)
Mean ± SD	44.7±13.7	49.5±15.4	47.9±14.3
Range	15–73	14–87	21–72
Sex, n (%)
Men	19(37)	45(39)	14(26)
Women	32(63)	70(61)	40(74)
Depressed, n (%)
Yes	8(16)	19(17)	7(13)
No	43(84)	96(83)	47(87)
Comorbidities, n (%)
0	33(65)	81(70)	38(70)
1	12(23)	28(24)	13(24)
≥2	6(12)	6(6)	3(6)
Smoking, n (%)
Yes	2(4)	3(3)	3(6)
No	49(96)	112(97)	51(94)

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Results 

Descriptive subject information concerning age, sex, and comorbidities is described in table 2. The mean age was approximately 47 years and more than half of the subjects were women. The 3 groups were similar in terms of all patient characteristics with the exception of sex. The chronic group had a higher percentage of women.

Mean functional outcome scores and the mean functional improvement from pretherapy to post-therapy are presented in table 3. No significant differences in initial function (P=.10) or functional outcome scores (P=.10) existed among the groups. Persons in the chronic group had significantly less functional improvement than persons in the acute group (P≤.05). Significant differences were found within each of the groups between pretreatment and post-treatment function scores. The average functional improvement for the acute group was 15.3 points, 13.1 points for the subacute group, and 8.1 points for the chronic group.

Table 3. Mean Assessment Measure Values

NOTE. Values are mean ± SD.

Figure 1 shows the raw pain scores at the initial visit and at discharge for each of the groups. The decrease in pain intensity from pretreatment to post-treatment was significant for all groups (P<.05). The median percentage improvement scores for pain and perceived recovery are shown in table 4. There was no significant difference in percent decrease in pain when comparing acute, subacute, and chronic groups. However, the median percent decrease in pain was only 49% for the chronic group, whereas the median scores for the acute and subacute were 55% and 60%, respectively. The median percentage improvement score for perceived recovery was significantly lower for the chronic group than for the acute group (P=.05).

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• Fig 1. 

  Ratings on the pain VAS. Values are mean ± SD.

Table 4. Median Pain and Perceived Improvement Scores

Measures	Acute	Subacute	Chronic	P
Decrease in pain⁎ (%)	55	60	49	.32
Interquartile range	50–100	37–90	21–83
Perceived improvement† (%)	85	79	71	.05‡
Interquartile range	75–96	70–94	60–88

Linear regression analyses were used to identify variables having an independent association with the functional outcome score at discharge. ANOVA of the regression line confirmed that the relationship between the dependent and all independent variables is unlikely to have occurred by chance (F₄=29.70, P<.001). A model with age greater than 65 (P=.001), symptom duration (P=.05), and inclusion of mobilization or manipulation treatments (P=.02) fit the data well and explained 36% of the variance (table 5). Comorbidities and depression were significant in the univariate analysis but were not significant in the final model.

Table 5. Regression Model Explaining 36% of Variance in Functional Outcome

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Discussion 

The purposes of this study of patients with cervical disorders were to describe physical therapist treatment choices, determine functional outcomes after PT, care, and determine which variables were associated with enhanced function. The interventions selected by therapists associated with our study were not entirely consistent with results of previously published studies. As reported by Jette and Jette¹¹ and Jette and Delitto,¹³ flexibility exercises were a frequently noted individual intervention category in our study. Strengthening exercises and mobilization or manipulation techniques, though, were used much more frequently by our therapists. Strengthening exercises were reported in 78% to 87% of our patients’ episodes of care (see table 2), depending on the patient acuity level, compared with highs of 60% and 53% in the Jette and Jette¹¹ and Jette and Delitto¹³ studies, respectively. Similarly, mobilization or manipulation was reported in 63% to 81% of our episodes of care (see table 2), depending on the patient acuity level, compared with previously reported highs of 61%¹¹ and 42%.¹³ Last, heat modalities were infrequently used by our therapists (4%−17% depending on patient acuity level) compared with a previously reported 91%¹¹ and 87%.¹³ The comparison of studies’ results reveals a trend toward a more active approach (exercise) to rehabilitation, combined with use of mobilization or manipulation techniques. Some possible explanations for discrepancies between studies include: (1) variations between patient populations or clinical settings, (2) differences in therapists’ training or skill levels, or (3) more recent research findings with appropriate use of evidence-based practice. This trend of less use of passive modalities was also noted in a comparison of studies of patients with LBP receiving PT care.¹¹, ¹³, ²²

Very little is known regarding factors that predict conservative treatment outcomes for patients with cervical disorders, making it difficult to compare and contrast our findings with others. Our findings provide evidence that may begin to identify relevant patient and clinical factors when it comes to establishing an accurate patient prognosis. The linear regression analyses in this study revealed that age, initial level of function, timing of PT intervention, and receiving mobilization or manipulation interventions explained 36% of the variance in functional outcome as a measure of disability. Increased age may be a factor, considering that the incidence of comorbidities tends to increase with advancing age.

The duration between onset of symptoms and initiation of care had a significant association with the degree of improvement with earlier intervention (reduced time period between onset of symptoms and initiation of care) positively influencing patient outcome. One possible explanation is that the prolonged period of symptom duration presents with the increased potential of developing concomitant psychosocial factors. Patients with chronic neck and LBP and specific psychosocial issues showed poor recovery at the 1 year mark.²⁵, ²⁶ Our results are similar to studies investigating patients with LBP where authors have noted earlier intervention being associated with enhanced patient outcomes.²⁰, ²²

Besides providing cervical spine manual therapy interventions for this population, recent evidence supports the use of thoracic spine thrust mobilization or manipulation techniques for a subgroup of patients with neck pain.²⁷ Cleland et al²⁷ identified a clinical prediction rule consisting of 6 variables: (1) symptom duration of less than 30 days, (2) no symptoms distal to the shoulder, (3) looking up does not aggravate the neck pain, (4) Fear-Avoidance Back Questionnaire physical activity subscale score of less than 12, (5) diminished upper-thoracic spine kyphosis, and (6) cervical extension ROM less than 30°. If 3 of the 6 variables are present, the chance of having a successful rehabilitation outcome improved from 54% to 86%.²⁷

Study Limitations 

The lack of a control group and the use of multiple tests of significance in developing the regression analysis may limit the extent to which the study results can be generalized to the target population of patients who are candidates for PT. Also, this study was a retrospective clinical report, which precludes any conclusions about the effectiveness of the provided PT interventions. The study findings are based on analysis of a clinical database that is used to monitor patient outcomes and for quality improvement. Several possible biases related to the use of clinical databases and issues in using them for predicting outcomes have been clearly described by Pryor and Lee²⁸ and Jette and Jette.¹¹ These include: (1) database lacked information concerning specific impairments such as flexibility and muscle strength, (2) use of data to answer questions not determined a priori, (3) missing observations, (4) selection and referral bias, and (5) large number of variables may threaten the validity of the predictions. Despite these limitations, our results provide valuable information concerning the relationship of patient factors and choice of PT interventions to functional outcomes and the optimal timing of therapy services. If this study is to be repeated certain alterations in the methods may be useful: (1) a prospective design would decrease the possibility of selection bias, (2) a larger sample size would allow for analysis of additional variables (eg, the presence of specific comorbidities, patient psychosocial factors, patients with neck pain only vs those with radiculopathy) which may affect the response to rehabilitation, (3) investigation of interventions directed to other body regions and their impact on patient outcome, such as the thoracic mobilization or manipulation discussed by Cleland et al,²⁷ and (4) including a control group would allow assessment of customized therapy programs comparing various combinations of interventions, the sequencing of interventions, etc.

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Conclusions 

Predicting patient outcome in those with musculoskeletal disorders is a complex challenge facing clinicians.³ The importance of developing an appropriate intervention program for patients with cervical disorders along with an accurate prognosis is supported by the evidence describing the high cost of chronicity.¹, ², ⁴, ²⁹ Our results provide support for early initiation of therapy and including manual therapy as part of treatment. These results can be used to help establish an accurate patient prognosis, generate research hypotheses and for designing future research trials.

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