https://www.bbc.co.uk/news/uk-england-coventry-warwickshire-46357500

An avoidable tragedy unfolded because an employer did not want to ask questions of its employee’s health and ability to do a job safety.  Why don’t employers ask these questions? Are they embarrassed or just lazy?       

From the information published in the source to which you referred, the problem appears to have been much more than 'not monitoring-':

Mr Chander had been warned about his "erratic" driving by the company after four crashes in three years, the trial of facts found in September.

The bus company, which is part of Stagecoach group, admitted allowing Mr Chander to work more than 70-hours a week.

'Warning' after 4 crashes in 3 years is surely a very limp response to evidence of very serious risks to passesngers and the public when the driver has impairments that lack control.

It think this is symptomatic of our failure to grasp “human factors”. We seem more comfortable dealing with systems (eg policy and risk assessment documentation) or equipment rather than people.   Human beings are often seen as the problem so we tend to avoid dealing with them and hope if we have enough paperwork issues will disappear.  We have had a disagreement with a senior manager, who when told that staff might be cutting corners in his department, as a number of them were likely to be up for redundancy dismissed this by saying “They are professionals and can always be expected   to work in an appropriate manner” except experience shows that they are actually human beings and will do human things like cut corners or not tell people about health issues if they feel their livelihoods are at stake. It is the responsibility of managers not just to tick boxes but to actually manage their staff.

Interestingly...... there's a gap between the heading of this posting, 'The cost of not monitoring employee's health and work', which is the isssues and the question raised.

When someone repeatedly threatens the lives of others, he or she is not the most appropriate person to rely on for a valid answer to a question about his or her health.

Language of A Kurziel's question complicates matters a little by using the technical exprewsion 'human factors' in  framing the question.  'Human factors' includes errors and violaions which is mre relably and validly defined than the metaphor of 'cutting corners' for failure to accept leadership/management responsbilities.

In the circumstances, what A Kurziel refers to as'acutally managing' staff includes preventing them endangering themselves and/or others by withdrwing them from a very high hazard work situion. 

In the same manner,  today in contact sports e.g. rugby parrticular classes of prima facie injuries require a referee to have a player replaced while he/she has a 'head injury assessment'; risk management controls of this kind were introduced becuase neurosurgeons overcame the loud objections that such measures would \destroy the game as we know it', helped by the scale of compensation claims arising in American football.

I think a good example of people not telling their employer about conditions which may or may not affect their ability to do their job safely is the "Harry Clarke" incident in Glasgow on the 22nd December 2014.

The incident itself happened at 1430 in the afternoon.  Harry Clarke passed out while driving a bin lorry along Queen Street in Glasgow.  15 were injured and 6 killed.  The 2 other ops in the cab were unable to intervene to attempt regaining control of the vehicle.

It was decided Police Scotland would investigate - Harry Clarke provided no statement.  All of the options open to the police for prosecution required some form of intent, which he could not have if he was unconscious.  For various reasons, nobody else attempted a prosecution.

There was a distinct lack of satisfaction at the conclusion, so a fatal accident inquiry was held (22nd July 2015).  The format of a fatal accident inquiry means a person can refuse to go (at all), refuse to enter the box, and refuse to answer questions - Incriminating questions can be avoided so the information given can't be relied on in a potential future court case.

Harry Clarke had a medical condition that had led to him becoming unconscious at the wheel of a bus in 2010 - One of the conclusions at the end of this mess was because he didn't tell them about his medical condition (which it is strongly suspected he knew about), the doctors were unable to recommend he inform DVLA.

I have a Word document that I put together when I looked into this (not a huge document) that I can send you if you PM me your email address, as I was concerned when I realised there had been effectively no punishment for the crime.