The population of the world is ever-growing and has been doing so for hundreds of years. As a result, the number of patients, as expected, is increasing proportionally. The statement is trying to say that with shortage of resources, doctors’ main concern in the future would be whether to provide treatment or not.  The doctors must then make decisions about who requires the treatment more. 

The most obvious factor which will contribute to the increasing demand is the growing population. This occurs when the birth rate exceeds the death rate. Due to overpopulation, there will be shortage of food supply which will cause malnourishment on a wide scale. These people will require immediate medical attention. Similarly, the amount of pollution, whether it is air, noise or water, will increase. This will lead to people being affected by diseases such as lung cancer, cholera or typhoid. 
The resources required to treat an increasing number of patients will fall short. Such resources include medical tools, machinery (such as X-ray machines or MRI) and even the medical workforce. 

Others may argue that a doctor ‘should always act in a patient’s best interests’. Denying a treatment to a patient will certainly not uphold this statement. This would be opposing the very principle of the NHS. Refusing a treatment because someone else needs it more can be considered as passive euthanasia. 

There are a lot of ethical and moral issues with this situation. The government can play an important role in ensuring cost-effectiveness in the medical field. Equal consideration should be given to all patients no matter their condition.