Basically, the nature of personalized medicine is multidisciplinary approach to science. Its wide spread adoption will require the harmonization of many components; advances in technology; changes in health care infrastructure and medical practice convention; improvement in the efficiency and quality of healthcare delivery; diagnostic and therapeutic business models for genetically designed markets; attempts by government and private players to justify a new genre of tests and drugs; a different approach to regulatory oversight; and, of course, the ethical and legal issues that go along with the extensive use of genetic information in medical records.71)
The realization of personalized medicine relies on the input and contributions of a broad community of stakeholders, all working together toward a shared goal of harnessing breakthroughs in science and technology to improve patient care.
Kramer and Croswell72)
showed that the true value of cancer screening tests is clouded by four kinds of bias; lead time bias, healthy voluntary bias, length biased sampling, and overdiagnosis. Personalized medicine of CVDs faces similar challenges. CVDs are developed by complicated interactions between multiple genes and environmental factors, and epidemiological issues exist whether or not genetic/genomic factors are the confounder or independent factors.
Personalized medicine is already being practiced in the clinic, and the use of genomic tools, particularly in cardiology, has enhanced patient care. The integration of genomic research into the clinic needs to be standardized and streamlined. But there are limitations of personalized medicine. Multiple studies were performed, but the results of literature is discrepant and inconclusive in some instances.73)
Genetics accounts for an insufficient percentage of response variability for a given case or drug.25)
This might be due to inadequately powered studies, studying the different drug response phenotypes or patient populations (differences in allele frequencies), problems precisely measuring the phenotype, subtlety of functional effects of polymorphisms, focus on single SNPs instead of haplotypes, and failure to consider the complexity of drug response.74)
Nevertheless, few studies documenting genotype-guided therapy are better than the "usual care" approach, and few "point-of-care" tests available to determine a person's genetic make-up or protein expression.25)
The promise and final goals of personalized medicine, for which tangible evidence already exists, includes the ability to shift emphasis in medicine from reaction to prevention, enable the selection of optimal therapy and reduce trial-and-error prescribing, make the use of drugs safer by avoiding ADRs, increase patient compliance with treatment, reduce the time and cost of clinical trials, revive drugs that are failing in clinical trials or were withdrawn from the market, and reduce the overall cost of healthcare.75)
The Personalized Medicine Coalition75)
required a substantial effort on the alignment of laws, regulatory and insurance reimbursement policies, healthcare information technology, medical education, and research investment.
For personalized medicine to be successful, Califf and Ginsburg76)
emphasized the need to enhance infrastructure in terms of laboratory (i.e., biobanking; coordinated efforts, operational and informatics support, standards: genomic technologies; core laboratories, economies of scale) and bioinformatical infrastructures (informatics; reliable, interoperable EHRs, integration of research, clinical, molecular data: decision support; biostatistics; critical shortage must be addressed, physician training in quantitative skills: decision making; understanding of human decision making, biological, psychological and social factors, education of health care professionals).
Other important issues are the economic and legal systems, along with the education on the personalized medicine. Further integration of personalized medicine into the clinical workflow requires overcoming several barriers in education, accessibility, regulation, and reimbursement.
highlighted socioeconomic/regulatory and ethical issues related to personalized medicine, which differs from the traditional models of payment and regulation. Currently, tests are not covered by public or private payers, and are financially viable for only a select patient population. There will be need to defined roles of professional societies, regulatory agencies and congress in promoting personalized medicine.
Most of the commentators on personalized medicine describe urgent needs for education, for both doctors and patients to promote knowledge, perception, and awareness, related to personalized medicine. More than half of cardiologists do not feel confident in their understanding of personalized medicine,20)
and education/educational opportunities are insufficient.20)
In his report, the primary driver of short-term skeptics is that the three out of four cardiologists believe that a lack of patient outcome data is the primary challenge to the implementation of personalized medicine in their practice. Additionally, there are reimbursement concerns for these tests (68%), lack of formal physician education, such as CME on the topic (66%), and lack of guidance from professional societies/associations (55%) on personalized medicine.17)
In Canada, a strong majority of medical doctor respondents agreed that genetic testing and personalized medicine can have a positive impact on their practice; however, only 51% agreed that there is sufficient evidence to order such tests. Canadian physicians recognize the benefits of genetic testing and personalized medicine, but lack the education, information and support needed to effectively practice in this area.17)
In the next five years, 73% of cardiologists indicate that personalized medicine will have some measurable impact on patient treatment. Within the next 10 years, more than 9 out of 10 cardiologists believe that personalized medicine will have a larger role in cardiovascular therapy.15)
Cardiologists report that 6% of patients are asking about personalized medicine.20)
We should raise the awareness to patients on personalized medicine. A 2009 PricewaterhouseCoopers report found that 20-75% of patients respond to the drugs they are taking, but with genetic testing that response rate could improve "dramatically".