In my seminal paper, “Distance to health services influences insecticide-treated net possession and use among six to 59 month-old children in Malawi,” I indicated that Euclidean (straight line) measures of distance were just as good as more complicated, network based measures.
I didn’t include the graph showing how correlated the two were, but I wish I had and I can’t find it here my computer.
Every time I’ve done presentations of research of the association of distances to various things and health outcomes, someone inevitably asks why I didn’t use a more complex measure of actual travel paths. The idea is that no one walks in a straight line anywhere, but rather follows a road network, or even utilizes a number of transportation options which might be lost in a simple measure.
I always respond that a straight line distance is as good as any other when investigating relationships on a coarse scale. Inevitably, audiences are never convinced.
A new paper came out today, “Methods to measure potential spatial access to delivery care in low- and middle-income countries: a case study in rural Ghana” which compared the Euclidean measure with a number of more complex measurements.
The conclusion confirmed what I already knew, that the Euclidean measure is just as good in most cases, and the pain and cost of producing sexy and complicated ways of calculating distance just isn’t worth it.
It’s a pretty decent paper, but I wish they had put some graphs in to illustrate their points. It would be good to see exactly where the measures disagree.
Access to skilled attendance at childbirth is crucial to reduce maternal and newborn mortality. Several different measures of geographic access are used concurrently in public health research, with the assumption that sophisticated methods are generally better. Most of the evidence for this assumption comes from methodological comparisons in high-income countries. We compare different measures of travel impedance in a case study in Ghana’s Brong Ahafo region to determine if straight-line distance can be an adequate proxy for access to delivery care in certain low- and middle-income country (LMIC) settings.
We created a geospatial database, mapping population location in both compounds and village centroids, service locations for all health facilities offering delivery care, land-cover and a detailed road network. Six different measures were used to calculate travel impedance to health facilities (straight-line distance, network distance, network travel time and raster travel time, the latter two both mechanized and non-mechanized). The measures were compared using Spearman rank correlation coefficients, absolute differences, and the percentage of the same facilities identified as closest. We used logistic regression with robust standard errors to model the association of the different measures with health facility use for delivery in 9,306 births.
Non-mechanized measures were highly correlated with each other, and identified the same facilities as closest for approximately 80% of villages. Measures calculated from compounds identified the same closest facility as measures from village centroids for over 85% of births. For 90% of births, the aggregation error from using village centroids instead of compound locations was less than 35 minutes and less than 1.12 km. All non-mechanized measures showed an inverse association with facility use of similar magnitude, an approximately 67% reduction in odds of facility delivery per standard deviation increase in each measure (OR = 0.33).
Different data models and population locations produced comparable results in our case study, thus demonstrating that straight-line distance can be reasonably used as a proxy for potential spatial access in certain LMIC settings. The cost of obtaining individually geocoded population location and sophisticated measures of travel impedance should be weighed against the gain in accuracy.
The UN keeps data on migrations patterns around the world, tracking origin and destination countries and number of migrants (Trends in International Migrant Stock: Migrants by Destination and Origin). I took some time out and created this network visualization of origin and destination countries from 2010. Other years were available, but this is all I had time for.
The size of each node represents the number of countries from which migrants arrive. By far, the most connected country is the United States, accepting more people from more countries than any other place on the planet. Most areas of the network represent geographic regions. Note that Africa is clustered at the top, and pacific island countries are clustered at the bottom.
An interesting result is that countries tend to send migrants to other countries which are only slightly better off than they are. For example, Malawi sends most of its migrants to Zambia and Mozambique, and Zambians go to South Africa, whereas those countries do not reciprocate to countries poorer than them. Wealthy countries tend to be more cosmopolitan in their acceptance of migrants.
Click on the picture to explore a larger version of the graphic.
It has been announced that Bangui mayor Catherine Samba-Panza has been appointed the Interim President of the near anarchic Central African Republic.
Her ascension couldn’t come at a better time. The Central African Republic, fragile even in the best of times, has been slowly sinking into chaos. No one really knows how many people have been killed in the fighting between Christian and Muslim militias (though this shouldn’t be read as a religious conflict), but reports last year pegged more than 1000 civilian deaths within a two day span. Experts have started using the g-word.
From the NYT:
The interim president selected on Monday at a raucous, five-hour session of a “national transition council” of rebels, rivals and politicians was Catherine Samba-Panza, a French-educated lawyer with a reputation for integrity and no ties either to the Muslim rebels or the Christian militia. Her selection was greeted with cheers in the assembly hall and dancing outside. That she is a woman — the third female head of state in post-colonial Africa — was especially welcomed by many people who felt that men had done nothing but lead the country on its vicious downward spiral.
Though encouraging, it’s too early to tell if Ms. Samba-Panza will be able to contain the bloodshed in the CAR. Certainly, Liberia gained much under the leadership of Ellen Johnson Sirleaf, but it’s hard to say whether there’s been a great transformation in Malawi under Joyce Banda. Rwanda’s female majority Parliament is vastly preferable to Kenya’s (or the United States’) overpaid and corrupt boy’s club, however.
The conflagration in the CAR has been troubling for a number of reasons. First, it represents a general pattern of instability just below the Sahara. Neighboring South Sudan, which just recently obtained independence, is now facing a conflict ridden humanitarian crisis.
Second, the conflicts in South Sudan, the CAR, Northern Nigeria, Mali and Somalia rage on compromise the positive narrative of a newly prosperous and economically viable Africa. The 80’s and 90’s were a stain on the continent. Though I don’t foresee a return to the extended civil wars of Angola and Mozambique (for example), general regional instability compromises the ability to sustain development over the entire continent.
Third, even if the CAR manages to suppress the violence, there are few viable options for the long term economic future of this landlocked and historically marginalized country. Without a long term economic plan chances are high that tensions will flare up once more, setting the country back again.
Third day in TZ. Now that I don’t feel like n octogenarian, I might be able to put together a few comprehensible sentences.
Flew into Dar on Saturday after a grueling flight. Had the pleasure though of sitting next to a group of jolly Hungarian engineers. They were being chaperoned by two Catholic priests who proceeded to repeatedly order whiskey shots for everyone in the vicinity. Catholicism has its finer points.
Dar is bustling. A port town, it is the main point of entry and exit for all goofs bought and sold in TZ. Not nearly as walkable as Blantyre, and not neatly as dangerous as Nairobi. It’s q good mix, plus there’s great Indian food for cheap. TZ has some great seafood.
Left Sunday to make the 20 plus hour trip to Rukwa. Odd seeing zebras and elephants from the highway, but frightening to see the remains of multiple highway accidents. Still, the roads here are far superior to that of Malawi, and the vehicles acceptable.
Road construction is happening at a breakneck pace here , even in the far reaches of nowhere. Trucks line the highways bumper to bumper signaling a rapidly growing economy. Almost everything is available everywhere and it’s only getting better.
Western TZ is gorgeous. Just saw a sign for Malawi. Only a few hours apart but worlds apart economically.
That’s all for now…
Malawi’s President Bingu, or as he was officially known “His Excellency the President Ngwazi Professor Bingu wa Mutharika” died last Thursday.
His death has left a power vacuum in Malawi. Joyce Banda, the current Vice President constitutionally is expected to take power, but members of Bingu’s Democratic Progressive Party are seeking to block her appointment. Banda, though chosen as a running mate by Bingu himself, increasingly found herself at odds with Bingu’s increasingly autocratic Presidency and ultimately left the DPP to form her own political party. Bingu sought to cancel her vice presidential seat unsuccessfully. The Malawian Supreme Court ruled that she was still entitled to the seat.
Both groups within and outside of Malawi are calling for a swift transfer of power to Banda, including the United States.
Malawi could do worse than Banda. A former educator, Banda has sponsored numerous initiatives to expand educational opportunities for children and to increase female empowerment within Malawi. Since 1990, Banda’s National Association of Business Women has provided support and training for female entrepreneurs, reaching a wide network of approximately 30,000 people. She has sponsored health initiatives in Malawi and won numerous international awards. Most impressive, she quietly sponsored a task force to determine the extent of HIV in MSM populations, a dangerous undertaking in conservative Malawi. Forbes magazine listed Banda as the third most powerful woman in Africa. In short, Banda could be the breath of fresh air that Malawi requires.
Mutharika’s Presidency, though initially lauded due to his successful seed voucher program, which he boldly implemented against the advice of the World Bank and the IMF, fell into disgrace due to widespread fuel shortages and a dearth of foreign exchange. The increasingly dire situation led to mass protests all over Malawi, a state crackdown, and the deaths of 19 people. It is questionable though, as to whether Banda can solve these problems, much of which is due to international market forces out of the control of the domestic Presidency.
Of interest to me were the circumstances of Bingu’s death. Bingu collapsed on Thursday night and was rushed immediately to Kamuzu Central Hospital, a public facility. Upon presentation at the Kamuzu, workers realized that they were lacking epinephrine and had to run to a facility run by University of North Carolina to procure it. Bingu likely died because of problems of drug stocking in Malawian facilities and substandard levels of health delivery. Bingu died due to a problem endemic to all of Malawi. Ironically, the opulent President of Malawi died needlessly like that of even the poorest of Malawians.
What were originally intended as peaceful demonstrations, however, have quickly turned to violent riots. Bingu’s Democratic Progressive Party have dispatched trucks filled with machete waving thugs. Police and military, at the behest of the current government, have been reported to have been witnessed beating protesters.
A reporter for Capital Radio Malawi has been beaten by police in Zomba. Deaths and injuries are already being reported.
Worse yet, the chaos has allowed looters to break into store fronts, including the Bata Shoe Store in downtown Blantyre, which now sits empty. Women have ben spotted carting off groceries and household items from local stores.
Protesters have set fire to DPP vehicles, and a police station in Chirimba sits in flames, even as I write this.
The situation is quickly spiralling out of control, though news and pictures are proving difficult to come by. I can imagine that as night falls (very soon) things will only get worse.
DPP thugs are out in full force. The Nyasatimes reports:
The gang of machete-wielding youths took to the streets in DPP branded vehicles and stopped at several points, got out their vehicles and sharpened their pangas.
“It’s scary. They have literally blocked the main road and are sharpening their knives right on the tarmac and threatening
everyone,” a bank executive, who did not want to be named, told Reuters.
Bingu’s Young cadets wileding machetes
Eye witness report said they chanted the now familiar DPP war-cry in Malawi’s lingua franca, Chichewa: “Onyoza boma sagona, timpweteka! (“Those opposing government will not sleep, we will deal with them!”)
They also savagely attacked a Mandasi seller who appeared to have made“rude” remarks against the threats.
Update: Capital Radio reports: “The world is on Malawi, CNN, BBC, Aljazera, CCTV and more. Riots in Ndirande, Chitawira, Zingwangwa. Ndirande is a WAR ZONE.”
Update: 12:07 pm EST RT @ianchakhaza: The volatile township of Ndirande in Blantyre is erupting with reports of police using live ammunition there #July20 #Malawi 20 are reported dead.
(These photos came from Capital Radio Malawi)
Update: 12:21 pm Chirimba, across from teh Queens Hospital is in flames and people are still stoning the police