Chronic pain is a considerable health care problem in Europe and in the whole world (Breivik et al. 2013). Chronic pain causes suffering, distress and makes daily functioning more difficult. According to the International Association for the Study of Pain (IASP) the revised definition of pain is “an unpleasant sensory and
emotional experience associated with, or resembling that associated with, actual or potential tissue damage” (Raja et al. 2020). The transition from acute to chronic pain means a change from inflammation and peripheral tissue damage to more significant central sensitization and central nervous system mechanisms
(Schneiderhan et al. 2017). Chronic pain is an individual sensory and emotional
experience, which depends on meaning of the pain and the mental state of the person (Bushnell et al. 2013).
The latest systematic classification of the International Classification of Diseases (ICD 10) for chronic pain was developed by the IASP (Treede et al. 2019). In
collaboration with the WHO, an IASP Working Group has renewed the
classification, in which chronic pain is defined as pain that recurs or persists for more than three months. Chronic pain is divided into seven subgroups. One subgroup is “chronic primary pain”, where chronic pain may be considered a disease in its own right. Such conditions include fibromyalgia and non-specific low-back pain, among others. In the six other subgroups, pain is secondary as a symptom to a disease. These conditions are called chronic secondary pain:
“chronic cancer-related pain, chronic neuropathic pain, chronic secondary visceral pain, chronic post-traumatic and postsurgical pain, chronic secondary headache and orofacial pain, and chronic secondary musculoskeletal pain” (Treede et al.
2019).
In older people, pain is usually frequent, due to osteoarthritis, spine problems or neuropathic pain, for instance. Frequent pain can be defined as pain
experienced once or twice a week to daily (Helme and Gibson 1999).
1.3.1 Prevalence of chronic or frequent pain
The estimated worldwide prevalence of chronic pain was 10% in adults in a systematic review from 1990 to 2017 (Andrews et al. 2018). In another review in the UK, the prevalence varied from 35-51% (Fayaz et al. 2015). In some studies the prevalence of chronic pain increases to 62-74% in the over 75 age group (Fayaz et al. 2015, Karttunen et al. 2015, Rottenberg et al. 2015). Of the ‘oldest of the old’
aged 85 years and over, 28% experienced pain (Carmaciu et al. 2007).
In a Finnish population-based study the prevalence of daily chronic pain was 14% among adults aged 20-74 years (Mäntyselkä et al. 2003). A third of the older population has been found to suffer from frequent pain (Helme and Gibson 1999).
One community-based study of home-dwelling people aged 75 years or older found that a third (38 %) had daily pain (Mäntyselkä et al. 2004). In another Finnish study one quarter of the study population aged 62-86 years had experienced moderate to very severe pain intensity during the previous month; the prevalence of moderate to very severe pain-related interference was 20% (Marttinen et al.
2019).
1.3.2 Association of chronic or frequent pain and comorbidities with self-rated health in people with diabetes
Self-rated health (SRH) is a subjective measure in which people rate their health with an instrument. One instrument to measure SRH is a question of the SF-36 (Scogging et al. 2009): ‘‘In general, would you say that your health is excellent, very good, good, fair, or poor?’’
Chronic pain has an independent effect on disability, SRH and quality of life (Mäntyselkä et al. 2003, McDaid et al. 2013, Karttunen et al. 2015). It has been shown that SRH is independently and significantly associated with people having at least two chronic diseases (Ishizaki et al. 2019). HRQoL is recommended as a key factor when assessing pain management outcomes (Borsook et al. 2013).
Systematic reviews found an association between chronic pain and low health related quality of life (HRQoL) (Leadly et al. 2013, Nygaard et al. 2014). In Ireland it was found that each chronic condition studied (diabetes, cardiovascular disease, respiratory disease or chronic pain) had an independent effect on disability, SRH and QoL (McDaid et al. 2013).
Older patients in primary care who have poorer glycemic control, have lower HRQoLand functional capacity, especially regarding mobility and self-care
(Kamarul et al. 2010, Aro et al. 2018). If comorbidities are ignored, it can weaken a patient´s functioning, quality of life and mortality risk (Piette et al. 2006). A
systematic review with eighteen studies showed that physical exercise and glucose checks were frequently positive factors, while complications, hypertension, the duration of diabetes, and depression were negative factors associating with the quality of life of type 2 diabetes patients (Jing et al. 2018). Increased distress in people with diabetes, chronic pain, impaired ability to move, female gender, lower education and increased BMI seem to have a negative impact on the HrQol in patients with two or more chronic conditions (Kamradt et al. 2017)
In a Finnish study, frequent chronic pain was associated with SRH independently and even more strongly than chronic diseases including diabetes (Mäntyselkä et al.
2003). There are a few studies that show trends in SRH over time. A Finnish follow-up study aimed at analyzing changes in SRH, disabilities, comorbidities and
psychological wellbeing. These studies were conducted among people aged 75-85 years living in their homes. SHR improved in the 20 years follow-up time depite of the increased comorbidities (Karppinen et al. 2017)
1.3.3 The predictive importance of pain characteristics in quality of life, mood, cost and health care use
In a study from Australia, psychological factors mediated the relatioship between chronic pain and physical disability. The authors also concluded that chronic pain, interfering and severe pain were associated with physical disability (Hairi et al.
2013). In a study from Germany, researchers examined the association of pain and depression in community-dwelling older adults. The participants were asked about pain quality, severity, frequency, duration and location. The conclusion was that multisite pain and the number of painful body areas, pain frequency and severity were the best predictors of depression (Denkinger et al. 2014).
It has been shown that the more interfering pain is, the more older people use healthcare resources (Blyth et al. 2004, Kennedy et al. 2017). A swedish
population-based study found that chronic pain and its severity in people 65 and older was associated with increased costs to the community and a low quality of life (Bernfort et al. 2015).
1.3.4 Chronic or frequent pain in older people with diabetes
A few studies were found concerning pain in older people with and without diabetes (table 3). Most of them were interview studies (McCarthy et al. 2009, Sudore et al. 2012, Mcdaid et al. 2013) or based on questionnaires (Pico-Espinosa et al. 2017) or both (Baker et al. 2017). One of them was based on record data (Caughey et al. 2010). Although every study involved older people with diabetes, the comparison between people with and without diabetes was made only in half of the studies (McCarthy et al. 2009, McDaid et al. 2013, Pico-Espinosa et al. 2017).
In several studies, pain seems to be present in 20-35% of older people with diabetes (McCarthy et al. 2009, Caughey et al. 2010, Sudore et al. 2012). There was an association between diabetes and chronic pain (McDaid et al. 2013, Pico-Espinosa et al. 2017) except in one study (McCarthy et al. 2009), which was conducted in a restricted area of New York, which may explain the difference between it and the other studies (McCarthy et al. 2009). In one population-based study, people with diabetes had pain more often than those without diabetes (OR 1.43; 95% CI 1.17-1.75) (McDaid et al. 2017). In another study diabetes also seemed to predict frequent back, neck and/or shoulder pain (RR 1.65, 95% CI 1.23-2.18) (Pico-Espinosa et al. 2017).
Table 3. Frequent and chronic pain in older people with and without diabetes.
451 8215 adjusted risk ratio (RR) for occurrence of
*Databases and search terms: PubMed 2001- 13.8.2019: diabetes, neuropathic pain, chronic pain, frequent pain, older people; Scopus 1993-13.8.2019: TITLE-ABS (diabetes* AND ((chronic OR frequent*) W/4 pain) AND (aged OR elder* OR "old person*" OR "old people"
OR "older person*" OR "older people" OR "old adult*" OR "older adult*"))