Rehabilitation following surgery: clinical and psychological predictors of activity limitations.

PURPOSE/OBJECTIVE: Activity limitations following surgery are common, and patients may have an extended period of pain and rehabilitation. Inguinal hernia surgery is a common elective procedure. This study incorporated fear-avoidance models in investigating cognitive and emotional variables as potential risk factors for activity limitations 4 months after inguinal hernia surgery. METHOD: This was a prospective cohort study, predicting activity limitations 4 months postoperatively (Time 3 [T3]) from measures taken before surgery (Time 1, [T1]) and 1 week after surgery (Time 2 [T2]). The sample size at T1 was 135; response rates were 89% and 84% at T2 and T3 respectively. Questionnaires included measures of catastrophizing, fear of movement, depression, anxiety, optimism, perceived control over pain, pain, and activity limitations. Biomedical and surgical variables were recorded. Predictors of T3 activity limitations from T1 and T2 were examined in hierarchical multiple regression equations. RESULTS: Over half of participants (57.7%) reported activity limitations due to their hernia at 4 months post-surgery. Higher activity limitation levels were significantly predicted by older age, higher preoperative activity limitations, higher preoperative anxiety, and more severe postoperative pain and depression scores. CONCLUSIONS/IMPLICATIONS: Interventions to reduce preoperative anxiety and postoperative depression may lead to reduced 4-month activity limitations. However, the additional variance explained by psychological variables was low (ΔR² = 0.05). Our models, which included biomedical and surgical variables, accounted for less than 50% of the variance in activity limitations overall. Therefore, further investigation of psychological variables, particularly cognitions related specifically to activity behavior, would be merited.

Potential Pain Management Programmes in primary care. A UK-wide questionnaire and Delphi survey of experts.

BACKGROUND: Most chronic pain patients are treated in primary care and their management is often challenging. Secondary care- or private sector-based Pain Management Programmes (PMPs) offering intensive multidisciplinary approaches have been found to improve participants' physical performance and psychological well-being. OBJECTIVES: We aimed to identify the components and perceived outcomes of multidisciplinary PMPs in the UK and to explore expert health care providers' opinions about important characteristics of an ideal yet practical PMP for delivery in primary care. METHODS: All PMPs in the UK (n = 77), identified through the British Pain Society, were invited to participate. Each PMP was sent a postal questionnaire. We then conducted a modified Delphi survey with 18 pain management experts from a range of professional backgrounds. RESULTS: A representative from 54 (response rate 70.1%) PMPs completed a questionnaire. Most PMPs were delivered in National Health Service outpatient secondary care by physiotherapists (98%), psychologists (94%), pain specialists (61%), nurses (54%) and occupational therapists (52%). There was evidence of reasonably prolonged follow-up of participants and use of a range of clinical outcome measures. Consensus was reached on most components and outcomes of a potential primary care-based PMP. 'Necessary' components included training in, and information about, self-management, general fitness, posture and mobility. Input from a physiotherapist and clinical or health psychologist was identified as key to the PMP. Preferred patient outcome measures were related to emotional well-being, self-efficacy and coping and quality of life. CONCLUSION: Future research should look to design, deliver and evaluate a primary care-based intervention based on these findings.

The use of medication for chronic pain in primary care, and the potential for intervention by a practice-based pharmacist.

BACKGROUND AND OBJECTIVES: The majority of people with chronic pain use analgesics regularly. Ensuring their safe and appropriate use is important. This study aimed to describe patterns of analgesic prescribing in one general practice, devise a method of identifying chronic pain patients from prescribing records, and assess prescribing recommendations made after a pharmacist-led review of analgesic prescribing and identify the proportion of these acted on by GPs. METHODS: Prescribing records in a practice of 6720 patients were searched and 678 patients were identified as receiving prescriptions for analgesics. 230 were invited to participate and sent a questionnaire, including questions about chronic pain severity, general health and medications used. This was repeated after six months. The pharmacist completed a detailed medication review using information from medical records, questionnaires and personal interviews. Prescribing recommendations were made to GPs. RESULTS: 192 recommendations about safe or appropriate prescribing were made for 86% of participants after records review, 56% being directly related to analgesic use. After 6 months all recommendations had been implemented in 77% of the patients. Few additional recommendations were made after interview. There was little or no relationship with changes in chronic pain severity or general or psychological health. CONCLUSIONS: We have demonstrated a method of identifying patients with chronic pain in primary care, and the feasibility and acceptability of a pharmacist-led intervention. This is of potential value in primary care, as relevant prescribing recommendations were made for most patients although further research is required to assess these.

The 'number needed to sample' in primary care research. Comparison of two primary care sampling frames for chronic back pain.

BACKGROUND: Sampling for primary care research must strike a balance between efficiency and external validity. For most conditions, even a large population sample will yield a small number of cases, yet other sampling techniques risk problems with extrapolation of findings. OBJECTIVE: To compare the efficiency and external validity of two sampling methods for both an intervention study and epidemiological research in primary care--a convenience sample and a general population sample--comparing the response and follow-up rates, the demographic and clinical characteristics of each sample, and calculating the 'number needed to sample' (NNS) for a hypothetical randomized controlled trial. METHODS: In 1996, we selected two random samples of adults from 29 general practices in Grampian, for an epidemiological study of chronic pain. One sample of 4175 was identified by an electronic questionnaire that listed patients receiving regular analgesic prescriptions--the 'repeat prescription sample'. The other sample of 5036 was identified from all patients on practice lists--the 'general population sample'. Questionnaires, including demographic, pain and general health measures, were sent to all. A similar follow-up questionnaire was sent in 2000 to all those agreeing to participate in further research. We identified a potential group of subjects for a hypothetical trial in primary care based on a recently published trial (those aged 25-64, with severe chronic back pain, willing to participate in further research). RESULTS: The repeat prescription sample produced better response rates than the general sample overall (86% compared with 82%, P < 0.001), from both genders and from the oldest and youngest age groups. The NNS using convenience sampling was 10 for each member of the final potential trial sample, compared with 55 using general population sampling. There were important differences between the samples in age, marital and employment status, social class and educational level. However, among the potential trial sample, there were no demographic differences. Those from the repeat prescription sample had poorer indices than the general population sample in all pain and health measures. CONCLUSIONS: The repeat prescription sampling method was approximately five times more efficient than the general population method. However demographic and clinical differences in the repeat prescription sample might hamper extrapolation of findings to the general population, particularly in an epidemiological study, and demonstrate that simple comparison with age and gender of the target population is insufficient.

Factors related to the onset and persistence of chronic back pain in the community: results from a general population follow-up study.

INTRODUCTION: We compared the prevalence of chronic back pain (CBP) at two points 4 years apart and examined socio-demographic, health, and pain-related factors associated with its onset and persistence. METHOD: A random population sample of 2,184 adults was surveyed in 1996 and resurveyed in 2000. The questionnaire included chronic pain case definition questions (pain for 3 months or longer); the cause (1996) or site (2000) of any chronic pain; the Chronic Pain Grade questionnaire; the Level of Expressed Need (LEN) questionnaire; the SF-36 general health questionnaire; and demographic questions. Those with CBP in 1996 and 2000 had "persistent" CBP; those with CBP in 1996 but not 2000 had "recovered" CBP; those with CBP in 2000 but not 1996 had "new" CBP. RESULTS: Corrected response rates were 82.3% (1996) and 83.0% (2000). The sample prevalence of CBP was 16% (1996) and 27% (2000). Factors in 1996 independently associated with "persistent" compared with "recovered" CBP were preexisting arthritis, high LEN, poor mental health, and not living alone. Factors independently predicting "new" CBP compared with no previous CBP were previous chronic pain elsewhere and poor physical health. "Persistent" CBP was associated with more severe pain, higher LEN, and poorer general health than "new" CBP. DISCUSSION: CBP is a common and lasting problem, whose persistence and onset are predicted by clinical (especially pain) and help-seeking behavior factors, rather than socio-demographic. Prevention should focus on these factors.

Quantitative assessment of chronic postsurgical pain using the McGill Pain Questionnaire.

OBJECTIVES: The McGill Pain Questionnaire (MPQ) provides a quantitative profile of 3 major psychologic dimensions of pain: sensory-discriminative, motivational-affective, and cognitive-evaluative. Although the MPQ is frequently used as a pain measurement tool, no studies to date have compared the characteristics of chronic post-surgical pain after different surgical procedures using a quantitative scoring method. METHODS: Three separate questionnaire surveys were administered to patients who had undergone surgery at different time points between 1990 and 2000. Surgical procedures selected were mastectomy (n = 511 patients), inguinal hernia repair (n = 351 patients), and cardiac surgery via a central chest wound with or without saphenous vein harvesting (n = 1348 patients). A standard questionnaire format with the MPQ was used for each survey. The IASP definition of chronic pain, continuously or intermittently for longer than 3 months, was used with other criteria for pain location. The type of chronic pain was compared between the surgical populations using 3 different analytical methods: the Pain Rating Intensity score using scale values, (PRI-S); the Pain Rating Intensity using weighted rank values multiplied by scale value (PRI-R); and number of words chosen (NWC). RESULTS: The prevalence of chronic pain after mastectomy, inguinal herniorrhaphy, and median sternotomy with or without saphenectomy was 43%, 30%, and 39% respectively. Chronic pain most frequently reported was sensory-discriminative in quality with similar proportions across different surgical sites. Average PRI-S values after mastectomy, hernia repair, sternotomy (without postoperative anginal symptoms), and saphenectomy were 14.06, 13.00, 12.03, and 8.06 respectively. Analysis was conducted on cardiac patients who reported anginal symptoms with chronic post-surgical pain (PRI-S value 14.28). Patients with moderate and severe pain were more likely to choose more than 10 pain descriptors, regardless of the operative site (P < 0.05). DISCUSSION: The prevalence and characteristics of chronic pain was remarkably similar across different operative groups. This study is the first to quantitatively compare chronic post-surgical pain using similar methodologies in heterogeneous post-surgical populations.

A review of chronic pain after inguinal herniorrhaphy.

BACKGROUND: Chronic pain was believed to be a recognized but infrequent complication after inguinal hernia repair. Evidence suggests that patients with chronic pain place a considerable burden on health services. However, few scientific data on chronic pain after this common elective operation are available. OBJECTIVES: To review the frequency of chronic pain and to discuss etiological theories and current treatment options for patients with chronic post herniorrhaphy pain. MATERIALS AND METHODS: All studies of postoperative pain after inguinal hernia repair with a minimum follow-up period of 3 months, published between 1987 and 2000, were critically reviewed. RESULTS AND DISCUSSION: The frequency of chronic pain after inguinal hernia repair was found to be as high as 54%, much more than previously reported. Quality of life of these patients is affected. Chronic pain is reported less often after laparoscopic and mesh repairs. Recurrent hernia repair, preoperative pain, day case surgery, delayed onset of symptoms, and high pain scores in the first week after surgery, however, were identified to be risk factors for the development of chronic pain. Definition of chronic pain was not explicit in the majority of the reviewed studies. Accurate evaluation of the frequency of chronic pain will require standardization of definition and methods of assessment. Prospective studies are required to define the role of risk factors identified in this review.

Measuring the severity of chronic pain: a research perspective.

The authors of this review are members of the Aberdeen Pain Group, a group of multidisciplinary researchers who have been researching chronic pain for over 10 years. This review draws upon their experience to consider the measurement of chronic pain severity from a research perspective. The first half summarizes the requirements of a measure of pain severity for epidemiological research, describes a number of existing measures of pain severity and discusses the appropriateness of these instruments for measuring chronic pain as part of a postal epidemiological survey. The second half focuses on the use of the Chronic Pain Grade questionnaire by the Aberdeen Pain Group. The reliability and validity of this instrument as part of a postal questionnaire, its sensitivity to change over time, and how the use of such an instrument compares with retrospective perceptions of patients are all investigated. The review concludes with a brief discussion of future issues relating to the measurement of chronic pain severity, again from a research perspective.

Assessing change in chronic pain severity: the chronic pain grade compared with retrospective perceptions.

BACKGROUND: There is no standard method of measuring change in chronic pain severity. Clinical trials commonly use serial assessment scales, completed at two points in time, to estimate change in pain severity, while clinicians usually ask patients to make a retrospective assessment of change. How the two methods compare is not known. AIM: To assess different methods of measuring change in chronic pain severity, by comparing changes in scores on a serial measure of chronic pain severity using the Chronic Pain Grade (CPG) questionnaire and responders' retrospective perception of change in pain severity. DESIGN OF STUDY: Postal self-completion questionnaires. SETTING: The Grampian region of Scotland. METHOD: Postal questionnaires were sent in March and September 1998 to a random sample of 535 adults with chronic pain, drawn from responders to a postal survey of the region conducted in 1996. RESULTS: Corrected response rates of 87.5% and 90.7% were obtained. Over a six-month period poor levels of agreement were found, with responders' retrospective perceptions mirroring recorded changes in 41.8% of individuals (kappa = 0.081). A low partial correlation coefficient between the two measures (-0.209) was also found. Over a two-year period there were again poor levels of agreement, with responders' retrospective perceptions mirronng recorded changes in 35.2% of individuals (kappa = 0.071). A low partial correlation coefficient (-0.401) was again found. CONCLUSION: There was poor agreement and low correlation between two commonly used methods for assessing change in pain severity over time. This finding has important implications for both service practitioners and researchers.