Many of the health workforce skill mix studies examined whether patient health outcomes, quality of care, and costs differed among different skill mixes of health care service providers. The studies examined task shifting, particularly the development of new professional cadres designed to increase productive efficiency and reduce the time needed to scale up, resulting in increased patient access and a reduction in health worker training and wage bill costs.
Task shifting includes various scenarios, such as substituting tasks among professionals, delegating tasks to professionals with less training, including creating a new cadre, delegating tasks to non-professionals, or a combination of these [2
]. For example, the work can shift from specialist physicians to general practitioners, nurses, midwives, or assistant medical officers. Other cadre titles that participate in task shifting include clinical officer, assistant clinical officer, assistant nurse, auxiliary nurse, enrolled nurse, auxiliary health worker, health care assistant, assistant pharmacist, and community health worker.
The work can also be redistributed according to new categories of health workers. There are many examples of new professional cadres being developed, from health extension workers being trained in one year in vocational schools in Ethiopia, to assistant medical officers being trained in obstetrics in Mozambique, to physician assistants being trained in the United States [18
]. Task shifting, including the development of new professional cadres, has been occurring for decades in both high-income countries (e.g. in the USA, see Hooker) and low-income countries, but is seen by some as becoming more urgent in low-income countries because of health care needs for HIV/AIDS patients and overall health worker needs-based shortages [3
The review produced three main findings. First, the studies provide substantial evidence that task shifting is an important policy option to help alleviate health workforce shortages and skill mix imbalances, whether the shortages and imbalances are needs-based or economic demand-based. This finding is supported by other recent reviews of task shifting, including HIV/AIDS treatment and care provided by lay and community health workers in Africa, maternal and child health care as well as the management of infectious diseases by lay health workers, and doctor-nurse substitution in primary care in developed countries [22
]. As we discuss below, the reviews emphasized the success of task shifting depends on local contextual factors. Although the studies that evaluated task shifting were typically not based on an experimental design such as a randomized controlled trial (as noted by, e.g. Buchan and Dal Poz; and by Zurn et al.), there is substantial evidence from non-experimental studies [6
Several example studies are discussed next, and the first two are based on randomized controlled trials. In Kenya, no significant clinical differences were found between HIV/AIDS patients who received clinic-based antiretroviral therapy care versus primarily community-based care delivered by people living with HIV/AIDS who received pre-programmed personal digital assistants with decision support [26
]. In Uganda, non-physician clinicians (NPC) and physicians had considerable strength of agreement for HIV/AIDS patient assessment, particularly with the final antiretroviral therapy (ART) recommendation, WHO clinical stage assignment, and tuberculosis status assessment [27
]. Surgically trained assistant medical officers (tecnicos de cirurgia
[TC]) in Mozambique produced similar patient outcomes as compared to physician obstetricians and gynecologists, but the TC's cost of surgery was estimated to be one-quarter of physician specialists, and TC's provided over 90% of obstetric surgery delivered in district hospitals [19
]. Clinical officers and medical officers providing obstetric surgery in Malawi produced similar patient outcomes [29
]. Huicho and colleagues found that the number of years of pre-service training was generally not associated with the appropriate assessment, diagnosis, and treatment of young children in Bangladesh, Brazil, Tanzania, and Uganda [30
]. Lekoubou and colleagues reviewed the evidence of nurses managing chronic conditions, specifically hypertension and diabetes mellitus in sub-Saharan Africa, and concluded that they are a potentially promising cadre to efficiently manage these chronic conditions [31
]. While nurse-led care is common in sub-Saharan Africa, nurse-led care with a specific application to chronic diseases is relatively new.
In a mental health example, which used an experimental design, Rahman and colleagues found that lady health workers (community health workers) in Pakistan trained in cognitive behaviour techniques significantly lowered depression prevalence among new mothers more than lady health workers without the training [32
]. While outcomes were not compared to physician specialists and other psychosocial care providers, the study demonstrates the potential to train CHWs in mental health treatments (also see Patel [33
]). This is important, given that there is a large needs-based shortage of mental health workers in low- and middle-income countries [34
Second, while there is substantial evidence that task shifting has the potential to increase productive efficiency and reduce the time needed to scale up, there are a number of challenges, and results have not always been favourable. In the study by Zachariah et al. of task shifting in HIV/AIDS in sub-Saharan Africa, they note quality and safety concerns, professional and institutional resistance, and the need to sustain motivation and performance [36
]. For example, quality of care may decrease if CHWs are given complex tasks. In Kenya, where CHWs had broad responsibilities of diagnosing and treating children, a study found that 80% of all guideline-recommended procedures were performed correctly, but only 58% of ill children were prescribed all potentially life-saving treatments [37
]. The same is true in high-income countries: Buchan and Calman found that many questions remain on the efficacy of nurses replacing doctors prior to a patient receiving a diagnosis [38
]. In a systematic review of CHW studies in the United States, Viswanathan and colleagues found mixed evidence on participant behaviour change and health outcomes [39
]. Supervision and training is an important component for quality of care. Barber et al. found quality improvements at public health facilities in Indonesia that had at least one physician versus those that had none [16
]. The Ministry of Health in Mozambique suspended training of non-physician clinicians providing antiretroviral therapy until the training program could be revised, because of poor quality of care results [40
]. However, the particular type of supervision and training is sometimes difficult to measure and replicate in other settings.
The third finding is conceptual. When tasks have been shifted from traditional professional cadres (e.g. specialists, doctors or nurses) to new professional cadres, most studies compare the new cadre's productivity and patient outcomes to the traditional cadre's. The parallel comparison occurs between higher- and lower-skilled workers. However, the appropriate comparison is between the results from the care received by the new cadre and the results from the care the patient would have received--if any care at all--had the new cadre not been available. Verteuil articulated this point well in his response to Kruk et al.'s Mozambique study: "An appropriate comparator to tecnicos de cirurgia
would be a 'do nothing' comparator as opposed to using formally trained surgeons....a more realistic alternative for patients treated by tecnicos de cirurgia
would be no formal treatment at all, which would, it is presumed, result in far worse outcomes for the patients" [28
] (p. 1260). Additionally, the opportunity cost of task shifting needs be incorporated into an evaluation, because a cadre that has shifted tasks will no longer be able to perform its original tasks.
The use of cost effectiveness analysis helps ensure appropriate comparisons are made. For example, Hounton et al. found newborn case fatality rates after a caesarean section in Burkina Faso were highest among those performed by clinical officers (198 per 1000) versus general practitioners (125 per 1000) and versus obstetricians (99 per 1000) [41
]. By calculating the incremental cost effectiveness ratio, they found that the cost per avoided newborn fatality was only $200 when 1000 caesarean deliveries were performed by a general practitioner instead of a clinical officer, but the cost per avoided newborn fatality increased to $11 757 when 1000 caesarean deliveries were performed by an obstetrician versus a general practitioner (dollars expressed in 2006 United States dollars).
To generalize potential savings from task shifting, Scheffler et al. use simulations to illustrate how skill mix changes can mitigate overall wage bill gaps in sub-Saharan Africa in 2015 [42
]. They estimate that 31 sub-Saharan Africa countries will experience needs-based health workforce shortages in 2015, and estimate the annual wage bill required to eliminate these shortages to be approximately $2.6 billion (2007 U.S. dollars). Their simulations show this wage bill could be reduced, for example, by between 2% and 5% by increasing the needed nurse-plus-midwife-to-doctor ratio by 50%, assuming a nurse or midwife is between 0.7 and 0.9 as productive as a doctor. Fulton and Scheffler extend this simulation to include CHWs (as discussed in Section 2 of this article), and Babigumira and colleagues used a time-motion survey of CHWs and other workforce cadres to estimate savings from task shifting [8
]. The simulations provide a framework for policy makers to assess their own health workforce mix in the context of resource constraints.