Ghana study may indicate lower life expectancy for rhesus negatives

A March 2017 study by J.P. Kretchy from Eastern Ghana has shown the following blood type frequencies:

O+ 53.8%
A+ 17.6%
B+ 18.3%
AB+ 2.8%
O- 4.5%
A- 1.3%
B- 1.3%
AB- 0.2%

The sample size was 11,298 individuals.
A few things in the study stand out:
The total 58.3% O frequency is even high for continental African standards.
Women were found to be 4.4% rh negative while men 10.2%. This is a huge difference.
The highest variance was in blood type O negative where 1.6% of women and 7.4% of men have shown their presence. While the overall percentage of rhesus negatives was shown to be 7.3%, there is a significant drop-off in the older generation:
Age group/Rhesus negative frequency
0-20 8.2%
21-40 8.7%
41-60 5.0%
over 60 4.3%
Significant drop-offs have been observed among O negatives with 5.4%, 5.4%, 2.7% and 2.2% respectively.

Does this mean that rhesus negatives in Eastern Ghana have a lower life expectancy than rhesus positives? Do O negative women have it especially tough? Are O negative women likeliest to migrate out of Ghana? All of the above?

A higher sex-drive in rhesus negative women could potentially contribute to seeing an increase in rhesus negative frequencies among the younger generations, combined with a high likelihood for rhesus negatives to partner with another rhesus negative.

This increase of rhesus negative frequencies in younger generations vs. an assumed drop-off among older people would also be supported by data in neighboring nations being more similar to that of the 4.3% frequency among the over 60 year old ones in Eastern Ghana (e.g. 4.2% rhesus negatives in Ivory Coast).

But there are other factors which would rather project a higher percentage of rhesus negatives among older people such as a higher likelihood to be resistant to HIV/AIDS.

This is the first Ghana blood type frequency study which has been brought to my attention, so we need more information and data.

Source:

Distribution of ABO blood group/Rhesus factor in the Eastern Region of Ghana, towards effective blood bank inventory

See also:

Blood Type Frequencies by Country including the Rh Factor
Regions with highest rh negative percentages