Cleary James, Gelband Hellen, Wagner Judith
Despite substantial effort and expenditure, at least one-third of patients diagnosed with cancer in high-income countries (HICs) die of their disease within a few years of diagnosis (National Cancer Institute 2009). In low- and middle-income countries (LMICs), two-thirds succumb, because the cancer types prevalent in LMICs tend to have poor prognoses, most cancers are advanced when diagnosed, and even for curable cancers few people have access to effective cancer treatment. For rich and poor everywhere, cancer can cause pain and severe distress, especially during the last few months of life. Cancer-related pain is not the exclusive domain of those who die of cancer. Even many who are cured of their disease live with the long-term effects of the disease and its treatment; many of them live with pain, as do people with a range of chronic conditions other than cancer. For the majority of cancer patients in LMICs, the most effective and feasible intervention for pain control is medication. For mild pain, over-the-counter, inexpensive analgesic medicines can provide adequate relief. When these nonopioids no longer relieve pain, then weak opioids, such as codeine, may work. Cancer patients most often experience worsening pain as their cancer progresses; 70–80 percent progress to severe pain, which only strong opioid medicines can relieve. Other approaches are effective for specific pain indications; the most widely applicable are palliative radiotherapy and surgery. Chemotherapy, neurologic, psychological, and other approaches also can be effective (see Foley and others 2006 for a comprehensive listing). All but analgesic medications and psychological approaches require access to well-developed health care facilities; these are usually available in large urban areas of middle-income countries (MICs), although not necessarily in sufficient numbers, but they may not exist at all in low-income countries (LICs). For example, many countries have no radiotherapy centers, and many have only one center (International Atomic Energy Agency Directory of Radiotherapy Centres, http://www-naweb.iaea.org/nahu/dirac/default.asp). Palliative surgery and palliative radiotherapy are discussed further in chapters 13 and 14, respectively. The focus of this chapter is pain control medication, which can relieve most cancer pain and can be delivered at home, even in remote areas. Since 1990, the World Health Organization (WHO) and other bodies have offered definitions of palliative care. These definitions differ in specifics but share a common vision of care that emphasizes effective pain relief and a team approach to care throughout the course of the illness (Cleary and Carbone 1997; Foley and Gelband 2001; Morrison and Meier 2011; WHO 1990). The primary goal of palliative care is improving the quality of life of patients and those around them; it is not the prolongation of life or the hastening of death. Access to pain relief has been declared a human right (Brennan, Carr, and Cousins 2007; Gwyther, Brennan, and Harding 2009; International Pain Summit of the International Association for the Study of Pain 2011; Lohman, Schleifer, and Amon 2010). From a global perspective, the growth of palliative care has been largely limited to HICs, which also rank high on the Human Development Index (HDI). The availability of palliative care—using the availability of opioid medicines as a surrogate—is correlated with a country’s HDI. At the low end, the availability is almost nil, and repeated surveys have shown that this availability changed only marginally between 2006 and 2011 (Gilson and others 2013). In the previous edition of Disease Control Priorities in Developing Countries, Foley and others (2006) documented the global problem of low access to adequate pain relief in LMICs. Since then, a few countries have improved access, but these accomplishments are sporadic; in many countries, the change is negligible. Now, there is both cause for optimism and the view of a long road ahead. Efforts to support leaders in reforming policy and clinical practice in LMICs have grown and provide a basis for improvements (Cherny and others 2013; Cleary, Radbruch, and others 2013). This chapter describes the current state of pain relief in LMICs, consistent with WHO’s use of opioid consumption as a surrogate for access to palliative care in the Global Monitoring Framework for Noncommunicable Diseases (WHO 2013a). We describe the gaps in pain control access across countries, analyze the barriers to improving its delivery, and describe the costs and benefits that might accrue from removing the barriers. Evidence summarized in this chapter focuses on the modest costs and substantial benefits of providing pain control, and it supports increased efforts in the short term. Pain control medication and other aspects of palliative care can lead, rather than follow, increased efforts in cancer treatment, relying on interventions that are part of a more advanced cancer control and treatment infrastructure.
尽管付出了巨大努力和投入,但在高收入国家,至少三分之一的癌症确诊患者在确诊后的几年内死于癌症(美国国家癌症研究所,2009年)。在低收入和中等收入国家,三分之二的患者会因此丧命,这是因为低收入和中等收入国家普遍存在的癌症类型往往预后较差,大多数癌症在确诊时已处于晚期,而且即使是可治愈的癌症,也很少有人能获得有效的癌症治疗。无论贫富,癌症都会引发疼痛和严重不适,尤其是在生命的最后几个月。癌症相关疼痛并非癌症致死患者的专利。即使许多治愈了疾病的人也会承受疾病及其治疗带来的长期影响;他们中的许多人会遭受疼痛,患有癌症以外其他一系列慢性病的人也是如此。对于低收入和中等收入国家的大多数癌症患者来说,控制疼痛最有效且可行的干预措施是药物治疗。对于轻度疼痛,非处方、价格低廉的止痛药物就能提供足够的缓解。当这些非阿片类药物不再能缓解疼痛时,可使用弱阿片类药物,如可待因。随着癌症进展,癌症患者的疼痛往往会加剧;70%至80%的患者会发展为重度疼痛,只有强效阿片类药物才能缓解。其他方法对特定的疼痛症状有效;应用最广泛的是姑息性放疗和手术。化疗、神经学、心理学及其他方法也可能有效(有关全面列表,请参阅福利等人,2006年)。除了止痛药物和心理治疗方法外,其他方法都需要有完善的医疗设施;这些设施在中等收入国家的大城市通常可以获得,尽管数量不一定充足,但在低收入国家可能根本不存在。例如,许多国家没有放疗中心,许多国家只有一个中心(国际原子能机构放疗中心目录,http://www-naweb.iaea.org/nahu/dirac/default.asp)。第13章和第14章将分别进一步讨论姑息性手术和姑息性放疗。本章重点讨论止痛药物,它可以缓解大多数癌症疼痛,甚至在偏远地区也可以在家中使用。自1990年以来,世界卫生组织(WHO)和其他机构对姑息治疗给出了定义。这些定义在细节上有所不同,但都有一个共同的护理愿景,即强调在疾病全过程中有效缓解疼痛和采用团队护理方法(克利里和卡尔博内,1997年;福利和盖尔班德,2001年;莫里森和迈尔,2011年;WHO,1990年)。姑息治疗的主要目标是提高患者及其周围人的生活质量;而不是延长生命或加速死亡。获得止痛治疗已被宣布为一项人权(布伦南、卡尔和考辛斯,2007年;格威瑟、布伦南和哈丁,2009年;国际疼痛研究协会国际疼痛峰会,2011年;洛曼、施莱弗和阿蒙,2010年)。从全球角度来看,姑息治疗的发展主要局限于高收入国家,这些国家在人类发展指数(HDI)上也排名靠前。姑息治疗的可及性(以阿片类药物的可获得性作为替代指标)与一个国家的人类发展指数相关。在低水平上,可及性几乎为零,多次调查表明,2006年至2011年间这种可及性仅略有变化(吉尔森等人,2013年)。在《发展中国家疾病控制优先事项》的上一版中,福利等人(2006年)记录了低收入和中等收入国家在获得充分止痛治疗方面存在的全球问题。从那时起,一些国家在改善可及性方面取得了进展,但这些成就并不稳定;在许多国家,变化微乎其微。现在,既存在乐观的理由,也面临着漫长的道路。支持低收入和中等收入国家领导人改革政策和临床实践的努力有所增加,并为改善提供了基础(切尔尼等人,2013年;克利里、拉德布鲁赫等人,2013年)。本章描述了低收入和中等收入国家止痛治疗的现状,这与WHO在《非传染性疾病全球监测框架》中使用阿片类药物消费作为姑息治疗可及性替代指标的做法一致(WHO,2013a)。我们描述了各国在止痛治疗可及性方面的差距,分析了改善其提供的障碍,并描述了消除这些障碍可能带来的成本和收益。本章总结的证据侧重于提供止痛治疗的适度成本和巨大收益,并支持短期内加大努力。止痛药物及姑息治疗的其他方面可以引领而非跟随癌症治疗方面的努力增加,依靠的是作为更先进癌症控制和治疗基础设施一部分的干预措施。