Cancer pain is one of the most common, debilitating symptoms among cancer patients worldwide. Science lots of barriers limit developing countries toward optimal cancer pain management, cancer pain has emerged as a major and undertreated health problem in developing countries[25]. A previous study of 30 medical centers conducted in 2010 in China showed that the mean pain severity was 4.81 ± 2.27. 30 patients (5.09%) reported as no pain, 164 patients (27.85%) reported as mild pain, 266 patients (45.16%) and 129 patients (21.90%) reported as moderate and severe pain[26]. In our study, the average pain score in the last 24h was 3.23(SD = 2.16), with 62.7% of the patients reporting their average pain as mild pain. From here we see that the current cancer pain management is better than before. The result of pain severity in this study was close to Barbara A. Elliott, P’s result in America[27], Torill Fladvad’s result in 11 European countries[28], and better than what was reported among similar samples in Jordan[10], Israel[15], India[16], Portugal[29], but worse than the severity reported in Italy[30]. In addition, cancer pain had a moderate degree of interference on patients, and the impact on normal work was the largest. Work is generally considered to be most affected by pain[10].
Even though the results of our study show that the pain management has made progress in China, 29.3% and 8.0% patients reported moderate and severe pain, also, the mean pain relief was only 66.46(SD = 27.13). Therefore, cancer pain management is expected to be further improved.
Patients in this study reported a moderate level of pain knowledge (3.60 ± 1.90). This result is similar to a previous study in America in which it was showed the mean pain knowledge score was 3.35[31], and better than the result of a study in Israel(5.46 ± 1.28). The three items with the worst patient pain knowledge were “prognosis”, “drug tolerance” and “addiction risk”. The findings of patient pain knowledge in this study were consistent with results of attitudes or beliefs related studies, which suggested that tolerance, addiction and cancer prognosis were patients feared most[27, 32, 33]. Therefore, this study further confirms the influence of knowledge on belief. Moreover, family caregivers in our study also reported a moderate level of pain knowledge (3.57 ± 1.76). A study conducted in America in 2019 revealed consistent result[34]. What is interesting is that the three items with the worst pain knowledge of caregivers were consistent with those of patients. A systematic review indicated that attitudinal barriers to cancer pain management across patients, family caregivers and the general public are similar, and the fears of tolerance, side-effects were most commonly cited[35]. Understanding patients and family caregivers perspectives on cancer pain and its management are very important for continued successful pain management. And the education should be focused on the poorest pain knowledge.
The results showed that the use of strong opioids had the greatest impact on the outcome of pain management. The pain intensity of the patients using strong opioids was 1.172 times higher than that of other patients. This result indicates that the pain is still poorly controlled despite the use of strong opioids. Another study also showed that 106 of the 354 patients enrolled in the study took strong opioids but still reported severe pain[36]. Why did this happen? First, strong opioids are not effective for some of patients with refractory pain, if necessary, referral to a pain specialist and/or the use of interventional strategies should be considered[1]. In addition, opioids alone is not optimal for patients with neuropathic pain. Adjuvant analgesic should also be used. Third, according to adults pain guidelines, patients who report severe pain should use strong opioids. Then, pain reassessment should be performed at specified intervals to ensure that analgesic therapy is providing maximum benefit with minimal adverse effects[1]. However, a survey showed that 70% of doctors did not change previously prescribed analgesics based on patients’ current pain status[37]. Therefore, the standardization of pain treatment still needs to be strengthened.
Patients’ self-perceived performance status was one of the influencing factors of pain intensity in our study, and the worse the performance status, the severer the average pain. A previous study by Jin Y. Kim provided evidence that the prevalence of cancer pain was higher for patients with poor performance status[38]. In patients with poor performance status, physicians need to be more cautious in the titration of analgesics, the increase of analgesics doses, the interaction between analgesics and other drugs, and the treatment of side effects. So it is more difficult to management cancer pain in this population. One of the five essential concepts in the WHO approach to drug therapy of cancer pain is for the individual[39]. For better pain management outcomes, individualized pain treatment should be based on the patient's clinical condition, characteristics of pain, and patient-centered goals of care.
What consistent with our hypothesis was that patients' pain knowledge was a predictor of the pain management outcome, and two knowledge variables were significant. 6.7% of the variance was due to one patients’ knowledge variable-believing that patients are often given too much pain medicine. Patients who had this specific knowledge reported more pain and were perhaps less willing to increase the analgesic agents dose to relieve cancer pain. This relationship can be explained in two ways. It may be due to that this knowledge neutralizes the fears of side effects, tolerance, addiction and physical dependence. A previous study investigating patients’ pain barriers showed that the main barriers were concerning about tolerance, addiction and side effects[40]. Patients’ pain barriers result in reluctance to objectively report pain. Alternately, another possible explanation is the lack of knowledge that increasing need for pain medicine means that the pain has got worsened. A study supported this thesis revealed that patients who knew that an increased need for analgesics reflected a real increase in their pain reported better pain experience, compared to those who did not have that knowledge[27]. Another patient's pain knowledge that had an impact on pain management outcomes was fear of addiction. Patients were less willing to report pain and use pain medicine due to fear of addiction, resulting in worse pain experience. However the R2 on this variable was just 2.2%, which shows that this knowledge has a small effect on the pain of patients. Understanding patients knowledge of pain and implementing educational program may begin to diminish the imparities in the management of pain. It may similarly allow for programs to be tailored to fit the specific needs of the patient in the treatment and management of their cancer pain.
In the present study, pain management outcomes reported by patients were associated only a small way with family caregivers’ knowledge of cancer pain and its management. Even though the family caregivers’ pain knowledge on “efficacy of cancer pain management” and “patients are often given too much pain medicine” influenced patients’ pain severity, the effect was small. A systematic review published in 2019 provides strong evidence that lack of pain knowledge among cancer patients, family caregivers, professionals and the public were reported as one of the most common barriers to effective cancer pain management. This comprehensive systematic review included 36 studies about cancer pain knowledge or belief from 18 countries, but only 4 of them were conducted in family caregivers[35]. So more updated studies are needed to generate more contemporary data regarding to family caregivers. Further investigation is needed to determine how family caregivers’ pain knowledge plays a role in patient cancer pain management.
Our study also has some limitations. Firstly, convenience sampling method was used to recruit medical centers and patients. Even though the sample size was sufficient enough, the sample representativeness may be not very good.
Second, family caregivers but not primary family caregivers were investigated in our study.
Primary family caregivers involves more than general family caregivers in delivering care and support services to patients with cancer pain. Therefore, more attention should be paid to the primary caregivers in the future studies.
In summary, this study concludes that patients pain management outcomes, patients pain knowledge and family caregivers pain knowledge are at a moderate level. Moreover, this study reveals that pain management outcomes are obviously influenced by analgesics, performance status and pain knowledge of patients and family caregivers. Advancing pain management by standardizing and individualizing pain treatment, implementing tailored education program to patients and family caregivers are important to improve cancer pain management outcomes.