In an attempt to describe the mechanism, whereby acute pain develops into a chronic pain problem more specifically, the “fear-avoidance model” was developed. The fear-avoidance model is a specification of the above-mentioned model. Both models stress the role of cognitions and behavior, but the fear-avoidance model is more explicitly tailored to explain a possible road to chronicity and has a specific and exclusive focus on the role of pain-related fear. This model is based on the work of Lethem, Slade, Troup, and Bentley (1983), Philips (1987), and Waddell, Newton, Henderson, Somerville, and Main (1993) and was expanded on by Vlaeyen and Linton (2000, 2012). It has been successfully applied to explain pain and disability in the subgroup of people experiencing a considerable amount of fear across a wide range of pain problems. While the exact sequence of interrelationships between the variables in the fear-avoidance models has been contended (Bergbom, Boersma, & Linton, 2012; Wideman, Adams, & Sullivan, 2009), there is ample evidence supporting the validity of the model (Leeuw et al., 2007; Vancleef, Flink, Linton, & Vlaeyen, 2012; Vlaeyen & Linton, 2000, 2012).

In summary, the model (see Fig. 11.2) poses that, for most people, pain is appraised as an undesirable and unpleasant but, nonetheless, a nonthreatening experience (“no fear”). This judgment makes it likely that the individual engages in appropriate behavioral restrictions after injury, but also that painful movements are gradually confronted. Gradual confrontation of painful movements is then thought to increase the likelihood of healing and recovery. On the other hand, in a significant minority of people confronted with pain, the pain experience is interpreted as a serious threat. In other words, these individuals appraise the pain in a catastrophic way. Tendencies to engage in catastrophic thinking about pain are central in this model and are thought to be the result of multiple influences, such as predisposing factors (e.g., negative affectivity), as well as environmental influences (e.g., threatening illness information and observational learning). A catastrophic interpretation of pain is thought to lead to pain-related fear, such as fear of the pain itself or fear of (re) injury. Fear, in turn, promotes hypervigilance to pain and behavioral avoidance, fueled by beliefs that activity may cause damage and will exacerbate the pain. Lastly, long-term avoidance of activity can have a negative impact on physiological processes, and it can result in a more general withdrawal from positive reinforcers, leading to mood disturbances such as irritability, frustration, and depression. Both depression and disuse are associated with decreased pain thresholds and tolerance levels and might, in that way, promote the painful experience.

While the fear-avoidance model places a specific emphasis on the cognitive (negative thoughts such as catastrophizing) and behavioral (avoidance) processes in relation to pain-related fear, these processes may, in fact, cut across most psychosocial and somatic disorders, where individuals are confronted to deal with (persistent or recurrent) aversive inner states, such as anxiety and depression, or health-related complaints such as fatigue and sleep problems (Harvey, 2008). These processes have been coined transdiagnostic processes, and they appear to have in common the fact that they function to regulate negative-affective experiences. Indeed, recently, these processes have been put forward as a possible explanation of the high degree of co-occurrence that has been found between pain and anxiety disorders (Asmundson & Katz, 2009; Sharp & Harvey, 2001). Specifically, there is evidence that relationships between pain and emotional disorders can be explained by shared vulnerability, such as anxiety sensitivity, and by maintaining cognitive and behavioral factors, such as negative cognitive appraisal, worry, covert, and overt avoidance (Asmundson & Katz, 2009).

Recent developments in pain psychology research extend the possible emotional regulatory function of cognitive and behavioral processes by emphasizing contextual factors (Hadjistavropoulos et al., 2011). For example, while the fear-avoidance model highlights the close interrelationship among catastrophizing, fear, and avoidance behavior, another model (the communal coping model) highlights how catastrophizing may perform a regulatory function in the interpersonal and communicative context. In this model, an important function of catastrophizing is thought to be to elicit support and reassurance. Several studies have confirmed that people high on catastrophizing are more interpersonally expressive concerning their pain, possibly with the function to seek support and reassurance and, through this, find emotional relief (Cano, Leong, Williams, May, & Lutz, 2012; Thibault, Loisel, Durand, Catchlove, & Sullivan, 2008). Eccleston and Crombez (2007) presented a reorientation of the fear-avoidance and communal coping models that attempts to take the functions of catastrophizing into account. Their “misdirected problem-solving” model largely reframes pain catastrophizing as worry and focuses on the function of worry in the context of persisting pain. While they describe worry as a generally adaptive mental problem-solving process, they stress that, in the context of chronic pain, worry can become maladaptive and “misdirected.” Specifically, if individuals define their persisting pain as a biomedical problem that needs to be cured, this narrow problem definition, and the consequent goal orientation and pursuit of pain relief, may actually increase the likelihood that individuals get “stuck” in a loop of mental, as well as behavioral, problem-solving. This loop is easily characterized by failure because the goal is diffuse or, in fact, impossible to attain. In the end, a situation may arise where an individual is trapped in a state where, on the one hand, progress toward a goal is not being made while, on the other hand, the individual is not able to abandon the goal. This may then lead to negative, persistent, and unconstructive worry in the form of pain catastrophizing, as well as behavioral avoidance. In other words, besides a threat appraisal and an interpersonal mode of communication, pain catastrophizing in this framework is seen as perseverant and inflexible cognitive attempts to solve an insoluble problem (Aldrich, Eccleston, & Crombez, 2000).

Indeed catastrophizing can, in general, be conceptualized as a form of negative repetitive thinking about a current concern which is abstract, intrusive, and difficult to disengage from (Flink et al., 2013). This account of the function of repetitive thought in the form of worry, behavioral avoidance, and safety seeking seems indeed shared across a wide range of problem areas (Mansell, Harvey, Watkins, & Shafran, 2008; Sharp & Harvey, 2001; Smith & Alloy, 2009; Watkins, 2008). These transdiagnostic processes may be powerful drivers of the chronification process, and they have clear implications for clinical management.

Improving our understanding of the mechanisms that underlie the development of chronicity has implications for clinical management and prevention. The importance of emotional, cognitive, and behavioral factors in the developmental process, from acute pain to a chronic disability, implies that assessing as well as addressing these factors is pivotal. However, while psychosocial theories and models about pain have provided a better understanding about the development of a chronic problem, they are abstract, and the immediate implications for clinical management may be less clear. Therefore, Table 11.1 summarizes some important general implications that can be extracted from the above account of psychosocial processes and models of pain experience.

As highlighted in Table 11.1, the possibility for prevention of chronicity would be enhanced if the psychosocial factors that impact on pain outcomes would be routinely assessed when they are already in the acute and subacute stages of development. In several ways, early screening for risk could play a key role in secondary prevention. First, it may be beneficial in directing preventive interventions, specifically to those who need it the most. Second, it might direct attention to those factors that are most pertinent and modifiable. It would help clinicians and researchers to target and develop the content of the intervention to the actual problems, fueling the development of a specific individual. Third, it might provide primary care facilities that often do not have the resources for assessing psychosocial factors with a simple routine for ensuring assessment. Because psychosocial factors have been shown to predict the development of future pain and disability problems, they form the basis in screening procedures (Nicholas et al., 2011). However, note that many other factors (e.g., specific work-related factors, such as organizational support, job stress, and perceived workplace communication) predict the development of chronic (work) disability and may be included in screening procedures, not in the least in a return-to-work context (Shaw, van der Windt, Main, Loisel, & Linton, 2009). Choice of a screening tool may well be dependent on the purpose and setting. In order to aid in the assessment of psychosocial factors, as well as to communicate with patients and implement early intervention, the Örebro Musculoskeletal Pain Screening Questionnaire (ÖMSPQ) was developed and psychometrically tested (Ektor-Andersen, Örbaek, Ingvarsson, & Kullendorff, 2000; Hockings, McAuley, & Maher, 2008; Hurley et al., 2000; Hurley, Dusoir, McDonough, Moore, & David Baxter, 2001; Melloh et al., 2009). About 80 % of the people presenting with a (sub) acute back pain problem can be correctly classified using this screening instrument. This Questionnaire is a self-administered screening instrument for individuals with acute or subacute musculoskeletal pain, containing 25 (Boersma & Linton, 2002) or 10 (Linton, Nicholas, & MacDonald, 2011) questions, covering the most important psychosocial risk factors, including questions such as work-related variables, coping, function, stress, mood, and fear-avoidance beliefs. Table 11.2 presents the short, ten-item version. The ÖMSPQ screening tool could, in addition to providing a rough estimate of prognosis, be used to aid in clinical management and a more precise targeting of treatment. For example, while the scoring pattern can give a risk estimate, it can also be used to discuss specific problems with the patient and identify individual problem areas and planning intervention strategies.