Assessing the effect of cardiovascular disease on work productivity and financial loss among school teachers in Peninsular Malaysia: a nested case-control study

Introduction

Cardiovascular disease (CVD) is a general term for several medical disorders that affect the heart or blood vessels. It remains a global health threat affecting individuals of all races and selected occupations (Havranek et al., 2015). School teachers are not exempted from acquiring CVD, possibly attributed to the stressful teaching environment (Riechmann-Wolf et al., 2021).

Different types of CVD have negative effects on school teachers’ work productivity. For example, teachers with acute coronary syndrome (ACS) may have reduced exercise tolerance to climb stairs in schools or conduct physical education classes. Based on a meta-analysis, nearly 20% of ACS survivors did not resume work (Kai et al., 2022). Up to 75% of stroke survivors struggled in controlling their hand dexterity, making it difficult for teachers to write on the board or manipulate classroom materials. Stroke-related dysarthria may also impair an effective verbal communication and further jeopardize the teaching process. Approximately 44% of stroke survivors at working age were unable to return to work, with the consequent productivity loss of nearly 1.9 billion dollar in United Kingdom (UK) (Saka, McGuire & Wolfe, 2009). Congestive cardiac failure (CCF) survivors with reduced ejection fraction easily felt fatigued, limiting teachers’ ability to perform physically strenuous activities in the classroom. Most teachers who were treated for deep vein thrombosis (DVT) may not achieve full functional recovery post-hospitalization. This speculation is supported by a large population-based cohort study among 66,005 working adults, which found that DVT patients had an 80% higher risk of work-related disability compared to non-DVT individuals (Braekkan et al., 2016). Teachers with peripheral arterial disease (PAD) may not be able to walk continuously due to claudication pain. Thus, they may not be physically fit to lead field trips or extracurricular activities that require prolonged walking.

Absenteeism is a regularly used indicator to assess work productivity, which is defined as not remaining at work as scheduled. Notably the absenteeism rates of school teachers ranged from 15% to 45% in countries of Africa (O’Sullivan, 2022). In particular, teachers who self-reported poor health had a 70% higher odds of absenteeism (Coledam et al., 2021).

In contrast, presenteeism or working-while-ill is characterized by sick workers turning up for work but not functioning fully at the workplace due to an underlying disease (Johns, 2010). The prevalence of sickness presenteeism among school teachers is generally higher at 57.1% to 65.2% (Dudenhöffer et al., 2017; Rojas-Roque & López-Bonilla, 2022). Presenteeism seems to be common in the teaching profession (as compared to other professions which do not handle people) as it is challenging to assign a substitute to teach without knowing the study progress of students (Marklund et al., 2021). By addressing workplace productivity loss among the affected teachers, a healthier learning environment can be fostered in the school community, leading indirectly to better students’ academic performance.

On average, UK workers spend 35 hours weekly to work but lost only 30 days to presenteeism and absenteeism in a year (Wee et al., 2019). Malaysian workers spend about 44 hours weekly to work but 66 days are lost annually to presenteeism and absenteeism. This workplace productivity loss translated to about 4.53% of Malaysia’s gross domestic product in 2015 (Rasmussen, Sweeny & Sheehan, 2016). Plausible explanations of the comparatively lower workplace productivity loss in UK include existence of comprehensive workplace wellness programmes in most regions of UK and better work culture engaging workers’ participation, leading to generally better workers’ mental or physical wellbeing (Hassan et al., 2009). In Malaysia, workplace wellness programme is more prevalent in larger organizations with more financial resources and may not be present in small and medium-sized enterprises (Mohamed et al., 2022; Moy, Sallam & Wong, 2006).

The California Teachers Study (Pacheco et al., 2020; Willey et al., 2017), a large prospective teacher cohort in the United States (US) only focus on establishing the causal relationship spatiotemporally between lifestyle factors and incident CVD. There is no detailed description of CVD impact on teachers’ work productivity in schools across the Europe, US or the Asia continents. Thus, the effect of CVD on workplace productivity remains unclear among school teachers. This study aims to determine the workplace effect of CVD and its monetary implication among school teachers in Peninsular Malaysia. By estimating the economic consequences of incident CVD among the school teachers, proposal of workplace wellness programme and improvement of current sick leave policy in Malaysian schools can be justified to reduce or prevent workplace productivity loss.

Materials & Methods

Results

From the data linkage with three registries as mentioned above, there were 209 incident CVD cases. Eleven (5.3%) of them had passed away. Only 72 (34.4%) responded to our telephone calls and completed the questionnaire. There were 25 (12.0%) responded to our calls but declined to answer the questionnaire. The rest of the incident CVD cases were not contactable either did not answer to the calls (29.2%), phone number not in service (14.8%) or phone number not available (4.3%).

From the 72 teachers who answered the questionnaires, only 48 (66.7%) were still working. Slightly more than half of the cases were females (54.2%) with mean (±standard deviation) baseline age of 42.4 (±6.5) years old (Table 2). Ninety-nine percent of the controls were females, with a mean (±standard deviation) age being 36.2 (±6.9) years old.

Majority of cases (81.2%) and controls (83.9%) were of Malay ethnicity. Most cases and controls were predominantly married. Cases had higher proportions of laboratory-confirmed DM (21.3%), self-reported hypertension (16.7%), high LDL-C (80.9%) and high triglyceride (42.6%), as compared to controls.

Majority of the cases had ACS (73.9%), followed by stroke (15.2%), CCF (4.3%), DVT (4.3%) and PAD (2.2%). Table 3 demonstrates workplace productivity among these working teachers. The expected means duration of work in a week by the cases and controls were 35.35 (SE = 6.56) hours and 40.00 (SE = 3.22) hours, respectively. The expected means duration of work in a month by the cases and controls were 141.4 hours and 160 hours, respectively. However, the actual self-reported durations of work in a month by the cases and controls were lower at 125.66 (SE = 7.83) hours and 137.24 (SE = 3.84) hours, respectively. No statistically significant differences were noted between cases and controls for such parameters.

Mean scores of absolute absenteeism for cases and controls were valued at 15.74 (SE = 26.99) and 22.76 (SE = 13.24) respectively. In contrast, mean relative absenteeism for cases and controls were negatively valued at −0.12 (SE = 0.34) and −0.55 (SE = 0.17), respectively. There was no difference in absenteeism between cases and controls.

The self-rated job performance score during the past one month and the mean scores of absolute presenteeism were significantly different between cases and controls. The self-rated job performance score was lower [7.63 (SE = 0.21)] for cases compared to controls [8.60 (SE = 0.10)]. The mean scores of absolute presenteeism for cases (76.30, SE = 2.12) was also lower than controls (85.97, SE = 1.04) (p = 0.001, eta squared = 0.075). However, the mean relative presenteeism for cases and controls had no significant differences. In terms of the estimated monetary loss, the annual cost of presenteeism was different (p = 0.001, eta squared = 0.082) between cases (MYR 21,237.52) and controls (MYR 12,089.74) (Table 4).

Discussion

Overall, there was differential effect of an incident CVD on work productivity of the affected school teachers. Absenteeism portrayed no difference between cases and controls. As compared to controls, cases had lower self-rated job performance, lower absolute presenteeism and higher annual cost of presenteeism. However, there was no mean difference of relative presenteeism between cases and controls, suggesting a situation where teachers were still working despite being unwell, but their productivities were reduced within an acceptable range compared to their usual performance.

Both absolute and relative absenteeism did not differ between the cases or controls. In other words, incident CVD exerted impact onto teachers’ work absence irrespective of the diagnosis status. As compared to the average absolute absenteeism score of patients with common mental disorders in India (45.0 hours per month) (Kondapura et al., 2023), our teachers with incident CVD had lower scores (15.74 hours per month). As government servants, public school teachers in Malaysia are entitled for 90 days of paid sick leave, which might explain a lower absolute absenteeism among our cases. Another possible explanation was that school teachers with incident CVD were granted similarly adequate medical leave (as compared to controls who might be absent due to other illnesses) by the treating physicians before being discharged from hospitals. Notably mean relative absenteeism was negatively valued in both cases and controls, signifying school teachers worked more than expected regardless of incident CVD. Such phenomenon might be a norm especially in schools where ratio of teachers to students was disproportionately low (Burdick-Will & Logan, 2017).

The concordance result of lower self-rated job performance and lower absolute presenteeism was expected since absolute presenteeism was a multiplier of the self-rated job performance by 10. In general, subjective self-rated wellbeing was associated with a lifetime CVD risk (Boehm & Kubzansky, 2012). Although different measuring tool was used, self-rated job performance (influenced by different degrees of job strain or job insecurity) was considered a strong predictor of incident CVD cases among middle-aged working women (Slopen et al., 2012). In this context, CVD patients often self-rated themselves to be poorer in own health or job parameters (Orimoloye et al., 2019).

Whilst the majority of teachers demonstrate dedication and commitment to their noble educational work, persistently working while unwell can pose health risks. Instances of low absolute presenteeism resulting from incident CVD among affected school teachers could potentially contribute to heightened emotional distress, subsequently impacting their overall job satisfaction. Left unaddressed, this could ultimately lead to burnout stemming from excessive presenteeism. Furthermore, colleagues might be compelled to compensate for the reduced workplace productivity of those who continue to work while unwell, which has the potential to create feelings of resentment and job-related stress. Consequently, the quality of interactions between teachers and students could be adversely affected.

Nevertheless, overestimation in annual cost of presenteeism could not be ruled out in the cases as the reduced job performance values were directly multiplied by the estimated reduced hours equivalent by the monthly income (Pauly et al., 2008). This finding was in contrast to the previously published research which concluded a lower monetary value imposed by presenteeism (than absenteeism) among healthcare workers (Rantanen & Tuominen, 2011).

The mean absolute presenteeism score among patients with underlying arthritis or similar rheumatological conditions was 74.1 (AlHeresh et al., 2017), comparable with our cases with incident CVD. However, another study which investigated employees with mental illness found a much lower mean absolute presenteeism score at 42.5 (Suzuki et al., 2014).

Conventionally, WHO-HPQ is recommended to measure health-related workplace productivity among employees suffering from chronic illnesses, but it has not been utilized to assess CVD patients (Kessler et al., 2004). A validation study confirmed that absolute presenteeism was the best parameter in WHO-HPQ which correlated well with health indicators (Scuffham, Vecchio & Whiteford, 2014). However, relative presenteeism which is a ratio of own job performance to others’ job performance may introduce errors as objective assessment of other colleagues’ job performance often could not be made, partially explaining the non-significance of relative presenteeism. While relative presenteeism showed no difference between cases and controls, the quality of teaching among affected teachers might still be compromised leading to impaired learning process among the students.

The annual cost of presenteeism is anticipated to rise with a decrease in absolute presenteeism. This is due to the necessity of subtracting the parameter associated with presenteeism, specifically ’self-rated work performance,’ in the formula for calculating the annual cost of presenteeism. In 2017, an estimated US$ 378 billion (MYR 1.76 trillion) was lost due to CVD in the US while the direct healthcare cost of CVD in Malaysia was reported to be approximately MYR 3.93 billion during the same year (Malaysia MoH, 2022). No other comparison could be made on presenteeism caused by CVD as there was no detailed cost analysis in this aspect. Thus far, most published studies in US focused on workplace absenteeism and did not analyse on presenteeism (Song et al., 2015). Presenteeism may be more difficult to quantify since there was no single measure outcome which was deemed as a gold standard.

While interpreting the findings, there are a few limitations which warrant discussion. Firstly, there was a small event rate with high non-response rate. Therefore, we could not conduct further regression analyses. It was also not possible to completely eliminate selection bias, specifically sampling bias. Matching on age or gender was not done as a matched design reduced effective sample size. Nonetheless, the use of advance statistical methods such as bootstrapping and ANCOVA adjusting for propensity scoring as a covariate reduced the error variance. In addition, random selection of controls minimized selection bias since the controls were chosen without preconceived criteria based on multiple exposures. The short version of WHO-HPQ may not be able to capture the complexity and nuances of health-related work productivity comprehensively. Nevertheless, the short version of WHO-HPQ was more likely to be fully completed by the participants. Finally, the cost estimates of productivity loss were based on recalls and therefore subjected to self-report bias.

This study outlined the importance in mitigating incident CVD and provided convincing evidence for CVD prevention programmes. Goal three for health in Sustainable Development Goals (SDG) emphasized on ensuring healthy lives besides promoting wellbeing at all ages, while one of the clause of goal four in SDG stated that qualified teachers should be increased by 2030. Since a higher absolute presenteeism score denotes a lesser extent of lost performance, strategies to increase absolute presenteeism or decrease annual cost of presenteeism should be designed and implemented for better workplace wellness among the teachers.

Conclusions

Absolute presenteeism was significantly different between cases and controls, with absenteeism parameters and relative presenteeism showing no difference. Absolute presenteeism was lower among school teachers who had incident CVD and the annual cost of presenteeism was costlier compared to teachers without incident CVD. Considering the substantial financial losses, it is advisable to implement strategies at increasing absolute presenteeism, which can lead to a reduction in the annual cost of presenteeism among school teachers experiencing incident CVD.

A recommended approach involves expanding workplace wellness programmes in Peninsular Malaysia, with a particular focus on school teachers who exhibit at least one traditional cardiovascular risk factor. These initiatives could include screening them for other common risk factors, accurately diagnosing symptomatic ones and intervening earlier to reduce the risk of acquiring incident CVD. Additionally, an alternative recommendation is to encourage the utilization of sick leave for teachers who have experienced an incident CVD. By allowing affected teachers to take the necessary time off to recover, the occurrence of absolute presenteeism following an incident CVD is expected to increase over time.

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